A cape on the Barents Sea shore of the island Novaya Zemlya was the target for the October 30, 1961 Tsar Bomba nuclear test.
In the early hours of October 30, 1961, a bomber took off from an airstrip in northern Russia and began its flight through cloudy skies over the frigid Arctic island of Novaya Zemlya. Slung below the plane’s belly was a nuclear bomb the size of a small school bus—the largest and most powerful bomb ever created.
At 11:32 a.m., the bombardier released the weapon. As the bomb fell, an enormous parachute unfurled to slow its descent, giving the pilot time to retreat to a safe distance. A minute or so later, the bomb detonated. A cameraman watching from the island recalled:
A fire-red ball of enormous size rose and grew. It grew larger and larger, and when it reached enormous size, it went up. Behind it, like a funnel, the whole earth seemed to be drawn in. The sight was fantastic, unreal, and the fireball looked like some other planet. It was an unearthly spectacle!
The flash alone lasted more than a minute. The fireball expanded to nearly six miles in diameter—large enough to include the entire urban core of Washington or San Francisco, or all of midtown and downtown Manhattan. Over several minutes it rose and mushroomed into a massive cloud. Within ten minutes, it had reached a height of 42 miles and a diameter of some 60 miles. One civilian witness remarked that it was “as if the Earth was killed.” Decades later, the weapon would be given the name it is most commonly known by today: Tsar Bomba, meaning “emperor bomb.”
A still frame from a once-secret Soviet documentary of the Tsar Bomba nuclear test, released by Rosatom in August 2020.
Designed to have a maximum explosive yield of 100 million tons (or 100 megatons) of TNT equivalent, the 60,000-pound monster bomb was detonated at only half its strength. Still, at 50 megatons, it was more than 3,300 times as powerful as the atomic bomb that killed at least 70,000 people in Hiroshima, and more than 40 times as powerful as the largest nuclear bomb in the US arsenal today. Its single test represents about one tenth of the total yield of all nuclear weapons ever tested by all nations.
At the time of its detonation, the Tsar Bomba held the world’s attention, largely as an object of infamy, recklessness, and terror. Within two years, though, the Soviet Union and the United States would sign and ratify the Limited Test Ban Treaty, prohibiting atmospheric nuclear weapons testing, and the 50-megaton bomb would fall into relative obscurity.
From the very beginning, the United States sought to minimize the importance of the 50-megaton test, and it became fashionable in both the United States and the former Soviet Union to dismiss it as a political stunt with little technical or strategic importance. But recently declassified files from the Kennedy administration now indicate that the Tsar Bomba was taken far more seriously as a weapon, and possibly as something to emulate, than ever was indicated publicly. And memoirs from former Soviet weapons workers, only recently available outside Russia, make clear that the gigantic bomb’s place in the history of Soviet thermonuclear weapons may be far more important than has been appreciated. Sixty years after the detonation, it’s now finally possible to piece together a deeper understanding of the creation of the Tsar Bomba and its broader impacts.
The Tsar Bomba is not just a subject for history; some of the same dynamics exist today. It is not just the story of a single weapon that was detonated six decades ago, but a parable about political posturing and technical enablement that applies just as acutely today. In a new era of nuclear weapons and delivery competition, the Tsar Bomba is a potent example of how nationalism, fear, and high-technology can combine in a fashion that is ultimately dangerous, wasteful, and pointless.
HIROSHIMA: 15 KT
NAGASAKI: 20 KT
B83 (largest currently deployed US warhead): 1.2 MT
RDS-37: 1.6 MT
CASTLE BRAVO: 15 MT
TSAR BOMBA: 50 MT
The 1954 Castle Bravo test produced an estimated yield of 15 megatons.
From kilotons to megatons to gigatons
Even before the first atomic bomb was built, scientists in the United States had conceived of an even larger weapon, the “Super,” which would use the energy of a fission bomb to power nuclear fusion reactions in the heavy hydrogen isotopes deuterium and tritium—resulting in a much more powerful weapon than one fueled by fission alone. Such a weapon, they reasoned, could be scaled up to the megaton range, a thousand-fold increase over the kiloton weapons they were contemplating for World War II. Los Alamos researchers were doing calculations on theoretical fission-ignited fusion bombs with yields of 100 megatons by October 1944.
But making the first hydrogen bombs took a bit more time than that. Post-war attempts to rein in the arms race failed, and the Soviet Union detonated its first atomic bomb in 1949. By the end of that year, a tense debate over whether a crash H-bomb program was the proper response to the loss of the American nuclear monopoly had leaked into the public, giving rise to speculation about the vast damage that could be caused by still-hypothetical megaton weapons. It was easy to apply scaling laws to see what the damage would be from such weapons. The 20-kiloton “Fat Man” bomb used against Nagasaki, for example, could devastate the downtown area of a large American city like San Francisco, Los Angeles, or New York. A single 10-megaton bomb, though, could destroy entire metro areas, subjecting over a thousand square miles to a crushing blast wave and searing heat, easily producing casualties in the millions. The radioactivity produced would also be multiplied many hundreds of times, creating the possibility of vast contamination.
By the spring of 1951, Edward Teller and Stanislaw Ulam at Los Alamos had developed their design for a workable hydrogen bomb. The idea was superficially simple: Use the radiation of an exploding fission bomb (the “primary”) to compress a special capsule that contained both fusionable and fissionable materials (the “secondary”). A proof-of-concept device (“Sausage”) was tested in November 1952, achieving an explosive yield of 10 megatons. A more compact, weaponized version (“Shrimp”) was detonated in March 1954 in the Castle Bravo test, achieving a much higher yield than anticipated (15 megatons, or 1,000 times as powerful as the bomb dropped on Hiroshima) and surprising the scientists with more radioactive fallout than expected (which required the evacuation of occupied atolls downwind from the Marshall Islands test site).
Only a few months later, in July 1954, Teller made it clear he thought 15 megatons was child’s play. At a secret meeting of the General Advisory Committee of the Atomic Energy Commission, Teller broached, as he put it, “the possibility of much bigger bangs.” At his Livermore laboratory, he reported, they were working on two new weapon designs, dubbed Gnomon and Sundial. Gnomon would be 1,000 megatons and would be used like a “primary” to set off Sundial, which would be 10,000 megatons. Most of Teller’s testimony remains classified to this day, but other scientists at the meeting recorded, after Teller had left, that they were “shocked” by his proposal. “It would contaminate the Earth,” one suggested. Physicist I. I. Rabi, by then an experienced Teller skeptic, suggested it was probably just an “advertising stunt.” But he was wrong; Livermore would for several years continue working on Gnomon, at least, and had even planned to test a prototype for the device in Operation Redwing in 1956 (but the test never took place).
All of which is to say that the idea of making hydrogen bombs in the hundreds-of-megatons yield range was hardly unusual in the late 1950s. If anything, it was tame compared to the gigaton ambitions of one of the H-bomb’s inventors. It is hard to convey the damage of a gigaton bomb, because at such yields many traditional scaling laws do not work (the bomb blows a hole in the atmosphere, essentially). However, a study from 1963 suggested that, if detonated 28 miles (45 kilometers) above the surface of the Earth, a 10,000-megaton weapon could set fires over an area 500 miles (800 kilometers) in diameter. Which is to say, an area about the size of France.
One of many heavily redacted pages in Cold War-era reports about US plans for “superbombs.” Edward Teller’s enthusiasm for “bigger bangs” is hinted at in these minutes from July 1954 meetings of the General Advisory Committee to the US Atomic Energy Commission.
The bomb’s physical dimensions would be gigantic: It would weigh 24–26 tons, with a length of 26 feet and a diameter of over 6 feet.
The Soviet Union had been interested in the Super for about as long, having received espionage information about the early American thermonuclear effort. The Soviets appear to have made their own path to the hydrogen bomb, though, first pursuing a single-stage design (“Sloika,” a reference to a layered pastry), tested in 1953, that could “only” be detonated at about half a megaton (though sub-megaton, it would still be 25 times as explosive as the Nagasaki bomb, and capable of killing millions if used on a major metropolis). In the spring of 1954, Andrei Sakharov, Yakov Zeldovich, and Yuri Trutnev, along with other Soviet physicists, developed their own version of a staged thermonuclear weapon, called RDS-37. The details of this are still somewhat cloudy, but it appears to have been a genuinely indigenous development, and it resulted in the test of a megaton-range weapon in 1955.
As in the United States, there were those in the Soviet Union who immediately began thinking of “bigger bangs.” In late 1955, Avraamiy P. Zavenyagin, a KGB general who was a minister of the nuclear program, proposed scaling up the program’s new H-bomb to a massive size. It would be nothing fundamentally innovative—the same RDS-37 design but with a lot more fuel, to produce a yield in the “many tens of megatons”; one document suggests 20-30 megatons. Work began on the weapon, dubbed RDS-202, in 1956, with design calculations made at Chelyabinsk-70 (the Soviet equivalent of the Livermore weapons laboratory) and procurement orders issued for the necessary materials.
The bomb’s physical dimensions would be gigantic: It would weigh 24–26 tons, with an eventual length of 26 feet (8 meters) and a diameter of over 6 feet (2 meters). Making the parts of such an oversized weapon proved almost beyond the capabilities of existing machine shops. The largest, front part of the casing alone required a “parquet” approach in which 1,520 smaller elements were welded together, and the casting of the internal spherical shapes required new manufacturing techniques.
But acting rapidly, the scientists and technicians had the bomb ready for testing in the fall of 1956 (Sakharov himself signed off on its warhead design). However, uncertainties about the possible effects of such a large weapon—and the scientists’ inability to reliably predict meteorological conditions that would affect both the distance of the blast effect and the fallout—led Soviet officials to postpone the test until additional studies could be done, which would end up taking years. Zavenyagin himself died on the last day of 1956, and, with him, so apparently did RDS-202. In March 1957, the Soviet government ordered that the project be put in long-term storage, and in 1958 decided to dismantle and recycle all the pieces of it. All that would remain in storage was the massive casing, which had been painstakingly engineered for its unusual ballistic properties.
Meanwhile, Soviet thermonuclear weapons design began to improve dramatically. Two young physicists at Arzamas-16 (the Soviet Los Alamos), Yuri Trutnev and Yuri Babaev, developed what they called a “new principle” for staged thermonuclear weapons. Project 49, as it was called, focused on optimizing the transfer of energy from the bomb’s primary to its secondary. This, coupled with better primaries and secondaries, allowed for a much more efficient warhead, capable of getting much bigger “bangs” out of a given weight and volume of material. Their new bomb design was finally tested in February 1958, with great success. Igor Kurchatov, the famed “father of the Soviet atomic bomb,” reported that year to the Congress of the Communist Party that now the Soviet Union had “even more powerful, more advanced, more reliable, more compact and cheaper atomic and hydrogen weapons.”
Another still frame from the recently released Soviet-era film about the Tsar Bomba test. The bomb casing was all that remained from RDS-202, an unsuccessful earlier Soviet superbomb project.
Planning for a 100-megaton bomb
By the end of 1958, both the United States and the Soviet Union would agree to a voluntary Test Ban Moratorium. Their stockpiles would still grow, but innovation in the arms race—at least when it came to the warheads—was deliberately stifled by the lack of nuclear testing. This would continue until 1961, when Soviet Premier Nikita Khrushchev decided, at last, that Soviet nuclear testing should resume.
Khrushchev would claim, in his memoirs, that he was pressured by the scientists and the military to resume testing. But it is also clear from those around him that he felt the need to look tough to the world—and to the newly inaugurated President John F. Kennedy, whom Khrushchev judged weak. And the real instigator would be the crisis in Berlin, which was coming to a head in 1961, and would only be resolved with the construction of the city’s notorious wall toward the end of the year.
The Soviet Union was also, it should be noted, in a somewhat precarious strategic position. The Red Army was huge and vast, and its nuclear arsenal was rapidly growing, but its delivery vehicles did not allow it to threaten the United States homeland directly and credibly. The Soviets could threaten by proxy, to be sure. But the United States had a many-fold advantage in nuclear weapons, many of them ringed around the Soviet borders. The Soviet Union had tested its first ICBMs, but there were scarcely any deployed. These same tensions would, in a few years, lead Khrushchev to base missiles in Cuba, but prior to that they made Khrushchev desperate to appear tough.
“Let the 100-megaton bomb hang over the capitalists like a sword of Damocles!”
On July 10, 1961, Khrushchev summoned the nuclear scientists from Arzamas-16 to the Kremlin, where he told them about his plan to resume testing that fall. Andrei Sakharov argued that further testing was unnecessary; Khrushchev was furious at his impertinence and snapped: “Sakharov, don’t try to tell us what to do or how to behave. We understand politics. I’d be a jellyfish and not Chairman of the Council of Ministers if I listened to people like Sakharov!”
Exactly how the idea of the 100-megaton device came up at this meeting is not entirely clear from the accounts, but it sounds like Khrushchev asked the scientists for proposals for future tests, and somebody (some authors say it was Trutnev) proposed that they build and detonate a 100-megaton bomb. Khrushchev seized upon the idea, reportedly announcing: “Let the 100-megaton bomb hang over the capitalists like a sword of Damocles!”
Later Russian accounts by participants claim Arzamas-16 scientists had been inspired, in part, by speculations about gigantic, gigaton-range bombs in the foreign press in May 1960. The physicist and designer Victor Adamski said that Sakharov and others tried to immediately assess the plausibility of the news reports, and came up with the schema that was ultimately used for the Tsar Bomba. They had initially apparently planned to design a smaller experiment, but they had somehow come across the preserved casing from the aborted RDS-202 bomb from 1956. The vastness of it apparently inspired them to go for a full-size test. But unlike the 1956 plan, they would use the newest Project 49 insights in developing this new bomb, making it far more sophisticated than a simple scaling-up of an old design; it would be over twice as powerful as RDS-202, despite being the same dimensions and weight. Sakharov, in his memoirs, said he had been thinking about “the initiative,” as he called it, well before any formal request was made. It was not just about the megatonnage for its own sake; it would need to be “an absolute record,” so that, perhaps, it would be the last series of atmospheric tests ever requested.
The 100-megaton bomb would be known internally as Project 602. The speed of its development is beyond impressive in retrospect: In a mere four months, the team would have to develop an entirely new weapon design for a totally untested yield range; build the device and fabricate the fissionable and fusionable material into the correct shapes; and devise a plan to safely test it. Sakharov would manage the whole project, with Trutnev and Babaev doing much of the design work, along with the young physicists Victor Adamski and Yuri Smirnov. Little has been released about the details of the design, but a few years ago two longtime participants in the Soviet and Russian nuclear programs revealed that it was what they called a “bifilar” design: There was a “main” thermonuclear unit in the center, with two “primaries” imploding it from either side (with a time difference between the two detonations of no more than 0.1 microseconds). This seems plausible given the documentary photographs of the bomb released by Russia after the Cold War, which definitely show one very compact “primary” bomb at the front end of the case, and hint at another at the back of the case. If this is true, it suggests that the 100-megaton bomb design was quite different from most thermonuclear weapons; there has never been a report of any American bombs, for example, that use multiple, simultaneous primaries.
Another Soviet weapons scientist, Leonid Feoktistov, from the rival Chelyabinsk-70 laboratory (which engineered the ballistics of the bomb), reported disappointment when he later looked at the warhead design: “It soon became clear that we are not talking about some kind of super-discovery, but just about an increase in weight and size.” Adamski, Smirnov, and Trutnev would disagree with this assessment entirely: “The bomb’s design was far from simple. Although it was based on already well-known principles, many things could have happened, including a failure to achieve the desired explosive yield. But our specialists made it so that the bomb went off flawlessly.”
Frame from the Tsar Bomba documentary released by Rosatom.
At the last minute, there were uncertainties about the design. Evsei Rabinowich, a colleague of Sakharov’s, had decided that the design would not work as planned. Sakharov disagreed. “Unfortunately,” Sakharov later recalled in his memoirs, “we lacked the mathematical tools I needed to prove this (partly because we had departed from precedent in our drive for a more powerful device).” In the end, Sakharov made “some changes” in the design, to minimize the margin of error, which were implemented only days before the test.
Sakharov also made one major change to the test plan. Even though the test bomb was a 100-megaton design, it would not be a 100-megaton detonation. In most thermonuclear weapons designs, at least half the yield comes from a final stage in which non-fissile atoms of uranium 238 are induced to fission by the high-energy neutrons produced by deuterium-tritium fusion reactions. Replacing the uranium 238 with an inert substance, in this case lead, would make the weapon half as powerful (50 megatons), and it would release far less fallout in the form of fission products.
Sakharov was already queasy about the long-term deaths from nuclear fallout, and he wanted to minimize the excess radioactivity produced by the test. In 1958, he had calculated that for every megaton of even “clean” nuclear weapons, there would be some 6,600 premature deaths over the next 8,000 years across the globe, owing to carbon atoms in the atmosphere that would become radioactive under the bomb’s neutron flux.
A few thousand deaths—even the 660,000 that he thought would be the result of a 100-megaton test—would be a tiny amount compared with the billions who would live and die over those millennia, but they were still deaths Sakharov considered himself partially responsible for. Had he not reduced its yield by half, the 100-megaton bomb would have contributed about half as many fission products as were released by all nuclear tests prior to the test moratorium. As it was, even a bomb that was only 3 percent fission wasn’t exactly clean in an objective sense—as it still released almost two megatons of fission products. But in a relative sense (comparing fission yield to total yield), it was one of the cleanest nuclear weapons ever tested. Again, Sakharov would later state that he believed that if this worked, it could essentially end atmospheric nuclear testing: The Soviets would be able to “squeeze everything out of this [testing series] so that it would be the last one.”
In August 1961, Khrushchev summoned scientists to a secret meeting at the Kremlin. A colonel stationed at Arzamas-16 was tasked with bringing a wooden dummy of the massive bomb—considerably scaled down, but still large enough that it required several officers to bring it into the conference room. He later reported that, as the scientists briefed Khrushchev, the Soviet leader “stroked the polished surface of the model for a long time, and looked at the superbomb with drunken eyes.” The colonel speculated that perhaps Khrushchev believed the bomb “gave him unprecedented power over the world.”
Russian Premier Nikita Khrushchev addresses a cheering rally in Moscow on June 21, 1961. Khrushchev threatened to sign a peace treaty with East Germany before the end of the year and said Russia would resume nuclear tests as soon as the United States started testing again. (AP Photo)
Announcing the test, denouncing the test
On August 30, 1961, the Soviet Union issued a statement that it was abandoning the test moratorium. It, of course, blamed the United States, claiming the Americans were on the threshold of starting up nuclear testing underground, and emphasizing the defensive nature of the Soviet arsenal. The statement also referred to big bombs: “The Soviet Union has worked out designs for creating a series of superpowerful nuclear bombs of 20, 30, 50, and 100 million tons of TNT.” But it did not yet directly threaten to test weapons of such high yields.
The response from Kennedy and others was predictably negative (according to one advisor who was there, the president’s first reaction was “unprintable”). The Kennedy administration then agreed that the United States, too, would resume nuclear testing. The tests the Atomic Energy Commission (AEC) had ready to go were low-yield underground tests, which the White House thought might “invite such adverse comment” when compared to the larger Soviet tests “as to be unacceptable.” But AEC Chairman Glenn Seaborg managed to convince Kennedy that it was a bad idea to try to immediately test larger devices, and the White House would later use this fallout-free series of tests as a contrast to the multi-megaton Soviet test series.
The Soviet hints of 100-megaton bombs provoked furious speculation in American newspapers, which reported unattributed sources saying that the United States could, if it wanted to, build and test 100-megaton weapons of its own, but that it chose not to. Some American scientists chimed in that weapons of such size were “too big” to be practical—that such a weapon would be strategically pointless. The argument, which would come up again and again in discussion of these bombs, was based on the way in which blast damage scales with yield. A 100-megaton bomb releases 10 times more energy than a 10-megaton bomb, but it does not do 10 times more damage. This is because the blast effects of explosions scale as a cubic root, not linearly. So a 10-megaton bomb detonated at an optimal altitude might do medium damage to a distance of 9.4 miles (15 kilometers) from ground zero, but a 100-megaton bomb “only” does the same amount of damage to 20.3 miles (33 kilometers). In other words, a 100-megaton explosion is only a little more than twice as damaging as a 10-megaton bomb. The weight of nuclear weapons, though, does roughly scale with their yield in a more linear fashion (design sophistication can vary this a bit), so a 100-megaton bomb weighs roughly 10 times more than a 10-megaton bomb, which makes it much more difficult to deploy on a bomber or missile.
The details can get much more complicated, depending on which effects one looks at (thermal radiation scales much better than blast damage), but the point that would be repeatedly made is that it is easier to deploy multiple lower-yield weapons than to deploy more massive weapons (and it is worth noting the absurdity of considering even one-megaton weapons, capable of utterly destroying most cities and many of their suburbs, to be “lower-yield”).
A November 1961 issue of LIFE magazine compared the destructive impact of a single, high-yield nuclear blast like Tsar Bomba to multiple lower-yield explosions with the same total megatonnage. The caption notes that even below 50 megatons, distributing lower-yield detonations would cause more damage.
In late August 1961, John McCloy, director of the US Disarmament Commission, reported publicly that, in a meeting with Khrushchev, the Soviet premier had said that they would need to test a 100-megaton weapon to learn whether their design worked. Soon after, the White House issued a statement denouncing Soviet testing plans and arguing that Soviet “threats of massive weapons” would not be able to “intimidate the world.” The White House recalled its representative from nuclear-testing negotiations in Geneva, and further talking points given to newspapers denounced talk of the giant bomb and its possible testing as “atomic blackmail” and “terrorism.” As Soviet nuclear testing began at the start of September, the protests continued. The Soviet test series was vigorous, with multiple tests per week, and yields ranging from less than a kiloton upward to a 12.5-megaton bomb by mid-October.
Finally, in his introductory speech to the Convocation of the 22nd Congress of the Communist Party of the Soviet Union on October 17, Khrushchev made public his plan for the Tsar Bomba:
Since I have digressed from the prepared text, I might as well say that the testing of our new nuclear weapons is going on very successfully. We shall complete it very soon—probably by the end of October. We shall evidently round out the tests by exploding a hydrogen bomb equivalent to 50 million tons of TNT. (Applause.) We have said that we have a bomb as powerful as 100 million tons of TNT. And we have it, too. But we are not going to explode it, because, even if exploded in the remotest of places, we are likely to break our own windows. (Stormy applause.) We will therefore not do it yet. But by exploding the 50-million bomb, we shall test the triggering device of the 100-million one. However, God grant, as people said in the old days, that we never have to explode those bombs over any territory. That is our fondest dream! (Stormy applause.)
The world response was immediate. The United States, of course, immediately denounced the plan as unnecessary: Even the development of 100-megaton bombs did not require a test of 50 megatons in strength, and the fact that the Soviets were doing it anyway “could only serve some unconfessed political purpose.” Newspapers picked up that the bomb would be tested around Halloween (a holiday not celebrated in the Soviet Union), and several editorial cartoons depicted Khrushchev in appropriate garb: on a broomstick, sprinkling fallout from a giant bomb; or as a trick-or-treater with a massive bomb in his bag of candy. By October 27, the United Nations had passed a resolution that “solemnly appealed” to the Soviet Union to refrain from testing a 50-megaton bomb.
All of this, of course, fell on deaf ears. The plan had been to test the “superbomb” since July, and the scientists at the Soviet weapons laboratories had finally prepared the warhead and its ungainly ballistic casing. These were assembled and shipped via a special railcar to northern Russia, where they were hung underneath a Tu-95V bomber that had been painted white to better reflect the thermal radiation of the blast. All the while, cameramen filmed the work, to create a documentary for Khrushchev to later show Communist Party officials and to impress foreign visitors (the 30-minute, top-secret film, “Testing of a clean hydrogen bomb with a capacity of 50 million tons,” was finally released by Rosatom a few years back).
Titled “Autumn Haze”, this October 1961 cartoon by Herb Block depicts Soviet premier Nikita Khruschev as a witch on a broomstick, just in time for Halloween.
Demonstrators raise a poster during protest processions near the Soviet Embassy in New Delhi, India on November 1, 1961. The poster depicts Soviet Premier Nikita Khrushchev throwing a 50-megaton nuclear bomb on civilization. Lettering reads, “Just a test… let me try on you.” (AP Photo)
Shots of the actual Tsar Bomba detonation and mushroom cloud collated from the previously secret Soviet documentary released by Rosatom in August 2020.
Sakharov and most of the weapons designers were not at the test, but they knew it worked because the detonation disrupted radio communications with the test site for 40 minutes. Despite being detonated low enough (about 13,000 feet) to be at risk of contacting the ground and creating significant local fallout, the blast wave “bounced” the fireball of the bomb upward. As a result, almost all the fallout shot into the stratosphere, where it would circle in the northern latitudes for years before coming down.
The global denunciation was, again, swift. Not yet knowing that the fission content of the bomb was deliberately reduced, the United States and others criticized the Soviet Union harshly for its contribution to global fallout. The White House said this was a political act, rather than a military one, and emphasized that such weapons did not change the balance of power: “There is no mystery about producing a 50-megaton bomb. … The United States Government considered this matter carefully several years ago and concluded that such weapons would not provide an essential military capability.”
The Kennedy administration’s official statement immediately following the Tsar Bomba test on October 30, 1961.
An American Tsar Bomba?
The Kennedy administration wasn’t bluffing about its ability to produce a 50-megaton bomb. As already discussed, the United States had been looking at weapons in the 10- to 100-megaton yield range for a long time and had even contemplated weapons in the gigaton range.
The closest the United States had previously come to weapons in what they called the “very high-yield” category came in the late 1950s, when Strategic Air Command (SAC) pushed vigorously for a 60-megaton bomb. Such a weapon was being eyed not only for its city-destroying powers (which would be substantive), but also for use in cracking open deeply-buried facilities—such as those within mountains, like the bunker the United States was then building at Raven Rock to ensure “continuity of government” in the event of nuclear war. General Thomas Power had designated this weapon as SAC’s top priority in 1957. But its incredible size increase over other weapons in the US arsenal attracted internal criticism and scrutiny. In 1957, AEC Commissioner Thomas Murray appealed to President Eisenhower directly as to whether such a massively powerful weapon was necessary, and whether it was consistent with “moral law with regard to the moderate and discriminate use of force in warfare.” This prompted Eisenhower to commission a study from the Pentagon and AEC on the need for such a weapon, and they ultimately concluded that it was probably “not appropriate” to develop such a weapon, largely because they expected adverse publicity both domestically and internationally. They concluded, however, that the “moral aspects of using large weapons do not differ from the use of any weapon having mass destruction potential.”
Despite this, SAC continued to push for the weapon, and expected it to be tested as part of Operation Hardtack in 1958. Eisenhower had, however, put a cap on total megatonnage for the test series (15 megatons, or 1,000 times more powerful than the bomb dropped on Hiroshima), and this scuttled the test. Scientists at the Livermore weapons laboratory assured SAC that they could provide them with two versions of such a weapon without testing, if desired; the first would be a 25,000-pound bomb with a 60-megaton yield, the second a 22,000-pound bomb of 45-megaton yield.
A few months after Sputnik, in 1958, the US Air Force Chief of Staff asked the AEC for a feasibility study of even larger weapons—between 100 and 1,000 megatons in yield. As an internal, once-secret Air Force history from 1967 reported: “The Air Staff concluded that it might be feasible but not desirable to use a 1,000-megaton weapon. Since lethal radioactivity might not be contained within the confines of an enemy state and since it might be impractical to even test such a weapon, the Air Force Council decided in April 1959 to postpone establishing a position on the issue.” Let that sink in: These were weapons too large for even the Eisenhower-era Air Force.
The largest weapon that the United States would ever field was also developed during this same, heady period: the Mark 41 thermonuclear bomb, with a yield of “approximately 25 megatons.” The United States has never formally declassified the exact yield of the Mark 41. A Congressman first divulged the weapon’s high yield a few days before the Soviet test, to reassure America’s people and allies that the country had powerful weapons of its own, and that each B-52 bomber could carry around 50 megatons of firepower in two such bombs. Unnamed AEC spokesmen then confirmed that this yield was essentially accurate. One rare document, potentially erroneously declassified, lists the exact yield as 23 megatons.
Details on the development of the Mark 41 are still highly classified, but it was apparently a three-stage weapon—the only such weapon ever fielded by the United States. It was never tested at its full strength. For the 1950s, this appeared, ultimately, to be all that the US military required. Work on such high-yield weapons seems to have been put on hold once the Test Moratorium began.
But when the Soviets announced their 100-megaton bomb and renewed testing, the old discussions of “very high-yield” weapons got a second wind. Shortly after Khrushchev first brought up the possibility of a 100-megaton test, Lt. General Austin Betts, the Deputy Director of Military Applications at the AEC, asked Los Alamos and Livermore to come up with estimates of what it would take to make an American weapon with a yield of 100 megatons. Within a week, he was given back-of-the-envelope estimates about the requirements for scaling up existing technology (like the Mark 41) to those yields, and how long it would take to field such a weapon.
Even after denouncing the Tsar Bomba as pointless terrorism, there were scientists and military planners working for the US government who were considering nuclear weapons with yields 20 times larger.
On October 18, 1961, AEC Chairman Glenn Seaborg wrote a memo to President Kennedy outlining the possibilities. A 100-megaton bomb, he explained, would weigh about 30,000 pounds and would be 6 feet in diameter and 12 feet in length. A 50-megaton bomb might be smaller but would still be extremely heavy (between 20,000 and 25,000 pounds). If this effort was given the “highest priority,” they could have such a weapon in the US stockpile within six months to a year, but such an effort would interfere with other programs. A test would be necessary to ensure reliability, but this could be done at reduced yield (no more than 10 megatons). The AEC had no reason to believe, he concluded, that the Soviet Union could not deliver their own such weapons to American targets.
A few days later, Seaborg met with weapons scientists to discuss building high-yield weapons. Betts initiated a discussion with Sandia National Laboratory over the feasibility of dropping weapons with yields of 30 or 50 megatons from a B-52, which would require using drogue parachutes to ensure the survival of the pilots. At the same time, a team of Livermore scientists got together to review the possibilities of a US return to nuclear testing. Along with ideas relating to more optimized designs and “clean” bombs deriving most of their yield from fusion, they were intrigued once again by Teller’s possibility of bigger bangs: “USSR high-yield tests have reawakened interest in high-yield testing by the United States. High-yield weapons (50 megatons to 1,000 megatons) should be reconsidered and re-evaluated for their possible military use.” Again, let that sink in: Even after denouncing the Tsar Bomba as pointless terrorism, there were scientists and military planners working for the US government who were considering nuclear weapons with yields 20 times larger.
In early 1962, one scientist at the Sandia lab reported to his colleagues about this sudden interest in superbombs, noting dryly that the Soviet detonation had “started some thinking in this country that there must be a good application for these things that has escaped our attention… the military would like to see the development of a few [very high-yield] bombs and would even feel good if a few were in the stockpile even though no known targets justify such weapons.”
Over the course of late 1961 through 1962, the United States itself engaged in a series of vigorous nuclear weapons tests. The first set, Operation Nougat (September 1961–June 1962), was underground at the Nevada Test Site, and featured only low-yield detonations (these were the tests that Kennedy had worried would be perceived as too small). The second, Operation Dominic (April 1962–October 1962) was a rapid series of over 30 nuclear detonations at Johnston Atoll and Kiribati in the Pacific Ocean. Dominic was the first series of atmospheric testing done by the United States since the end of the moratorium, and it involved a variety of activities, including testing new weapons concepts, detonating weapons in outer space, probing the electromagnetic pulse effect, and detonating the first fully “mated” system of a nuclear warhead and a launched missile.
While most of the Dominic tests were in the kiloton range, a few were megaton tests. Only one crept up to around 10 megatons; the United States prided itself, in press releases, on testing its warheads at less-than-full yield, to reduce fallout in the atmosphere. (The entire Dominic test series was about 40 megatons, less than the single Tsar Bomba shot.) Even though it does not appear that any of the Dominic shots were aimed at developing a 100-megaton bomb, several of the new designs did play key roles in the AEC’s thinking about “very high-yield” weapons. Notably, three of the tests were for a new, “revolutionary” weapons concept known as RIPPLE, developed at Livermore by weapons designer John Nuckolls. The details of RIPPLE are still classified, but it promised to get very high fusion yields out of relatively light packages by dramatically optimizing how the weapon produced nuclear fusion reactions.
The vigorous 1962 testing series, and the barely avoided catastrophe of the Cuban Missile Crisis, appear to have put a damper on these discussions temporarily. But by December, AEC Chairman Glenn Seaborg reported to the Secretary of Defense, Robert McNamara, that the AEC was prepared to develop an American Tsar Bomba if ordered to. Seaborg divided the possibilities into three categories. The first was to scale up existing weapons, like the Mark 41, to higher yields. This would be very quick, but the weapons would be extremely bulky. The second option was to use the new RIPPLE concept, which would get lighter weights but place unusual constraints on volume (probably because the secondary in a high-yield RIPPLE device would be spherical). Finally, there were weapons concepts “yet to be proven feasible” that would potentially achieve “the ultimate high yield, low weight, and acceptable volumes.” The AEC noted it would be possible—by diverting significant laboratory resources—to have devices ready to test by the end of 1963.
Much of the memo quoted above is still classified (though many versions of it exist, and some are less redacted than others), but there is one copy that contains some relevant technical information. Los Alamos had reported to Seaborg that they would be able within three years to build a 100-megaton bomb (of which some 20 to 30 megatons would be from fission, but “clean” options could be made as well) that would weigh 30,000 pounds and would be 23 feet long, with a diameter of 5.5 feet. Livermore claimed it could scale up a Mark 41 to high yields and have it weigh only 20,000 pounds, and it would only take one year. But Seaborg again cautioned that to pull any of this off would require a substantial investment of time and resources, and he would not do it without explicit direction from the president: “to produce high-yield weapons will require a scope of effort much larger than any previous AEC weaponization effort.”
A comparison of the “superbombs” developed or conceived by US and Soviet nuclear scientists. (Alex Wellerstein)
The Limited Test Ban Treaty
In 1963, the United States stood at a crossroads. Down one path was a new generation of “very high-yield” nuclear weapons with continued atmospheric nuclear testing. Down the other was the possibility of the Limited Test Ban Treaty, which would ban future atmospheric testing, effectively precluding the development of high-yield weapons.
Defense Secretary McNamara and the Joint Chiefs of Staff tentatively threw in their lot with the first path. In March 1963, McNamara established, and the Joint Chiefs concurred with, a formal development requirement for a “very high-yield” bomb that could be dropped from a B-52 bomber. “Specifically,” as Ross Gilpatric, the Deputy Secretary of Defense, outlined to Glenn Seaborg, “it is our desire to obtain the maximum yield possible compatible with the B-52 without requiring further nuclear tests.”
AEC Chairman Seaborg, though, seemed less eager—perhaps because of the aforementioned effort involved. Seaborg insisted that the president himself would have to be involved in this decision, because, he claimed, during the Eisenhower administration there developed an implicit policy that for weapons of such high yield, the labs and AEC would not work independently. Nonetheless, Seaborg duly reported that, according to the labs, the easiest high-yield bomb they could produce would be a scaled-up Mark 41, which would weigh (in the latest estimate) 35,000 pounds, with a 70-inch diameter, a length of 305 inches, and a yield of 50 megatons (but perhaps up to 65 megatons). This was roughly the maximum size that could fit into a B-52 bomb bay. The first production unit would not be ready until 1966, even if it was authorized immediately.
Meanwhile, the AEC Director of Military Applications had started to look at one thorny, non-nuclear part of the project: the massive ballistic case for the weapon, the same issue that had caused the Soviets so much hassle. The case for some of the newer high-yield designs, as with Tsar Bomba, might be too large to fit inside the B-52.
The same memo noted that Sandia had started to develop a new approach to testing known as “universal test vehicles,” or UTVs. These would have standardized ballistics and fuzing equipment that could deliver any warhead for testing purposes, so that test devices could be easily dropped from a plane even if they were still in early development. The original UTV would be the size of a B-53 bomb, quite large indeed, and capable of carrying any warhead that was at that time in the US arsenal. For weapons capable of carrying “very high yields,” however, an even larger test vehicle was being developed: the Big Test Vehicle, or BTV. It was the same size as the estimate Seaborg had given for a scaled-up, 50-megaton Mark 41: the largest size that could fit into a B-52. It required its own special transporter and looked like an immense cylinder.
Additionally, Sandia developed another vehicle that was even weirder, and perhaps more ominous: the Flashback Test Vehicle, intended for what was sometimes called Operation Flashback, and elsewhere called Project Breaker—an air-dropped gravity bomb casing so large it could not fit within a B-52 bomber. Like Tsar Bomba, it would be slung below the plane, half in the bomb bay and half out (with the bay doors removed). Project Breaker involved preparing to test a “very high-yield” warhead should atmospheric testing resume, initially on the argument that the US wanted it for its arsenal for use in the B-52 or the B-70 bomber. By the mid-1960s, this argument was seen as not very convincing, and so the justification for Breaker shifted instead to measuring the effects of such a weapon for defensive purposes. The exact yield for Breaker, or why the warhead design anticipated for Flashback would be too large for even the expansive dimensions of the BTV, are unclear, but these two “Test Vehicles” give us a concrete look at what an American Tsar Bomba would have looked like, at least in its initial drafts.
At more than 300 inches long and weighing some 45,000 pounds, the Big Test Vehicle, or BTV, was near the maximum payload of the B-52 bomber.
The Project Breaker, or Flashback, nuclear test vehicle was so large it had to be partly suspended outside of the B-52 bomb bay.
But while the AEC was beginning to explore this pathway, complications came up. One was political. The White House had denounced the Tsar Bomba and high-yield atmospheric testing. When William Foster, the head of the Arms Control and Disarmament Agency, which was attempting to broker disarmament talks with the Soviets, got wind of the US feasibility studies for “very high-yield” weapons, he urged Seaborg to proceed with caution. If it became known publicly that these studies were happening, Foster wrote, there would be an “effect on our negotiating position, political and psychological, and the consistency of such a development with the principles and purposes of our nuclear capabilities, as set forth in Presidential and other statements.” And indeed, at some point during this time period a restriction was put on the AEC prohibiting the development of weapons so large that their ballistic cases wouldn’t fit into existing airplanes, probably because the sight of such a thing would necessarily invite speculation (so to develop the Flashback Test Vehicle required express permission from the White House).
The Limited Test Ban Treaty was beginning to take shape at this time, with a very real possibility that the United States and Soviet Union would agree to ban all atmospheric nuclear testing. Underground testing, which the United States had demonstrated in 1961, would continue. But underground testing is limited to relatively low yields: To avoid “venting,” the fireball must be entirely contained underground—and an enormous fireball would require an enormous hole in the ground. (To put it into perspective: The fireball for a 50-megaton weapon has a radius of about 3 miles. The deepest active mine in the world is 2.5 miles deep, and the deepest hole in the world is only about 4 miles deep. Even the world’s highest mountain is only 5.5 miles tall.)
The take-away, as the AEC advised the White House and Congress, was that while there was still much the AEC could do to improve its nuclear arsenal with underground testing, the one area it wouldn’t be able to gain much knowledge was in very high yields. Furthermore, eventually the Soviet Union would be able to catch up with US capabilities in lower-yield weapons. So it really was an either-or situation: The United States could have superbombs, or it could have a Limited Test Ban Treaty. It could not have both.
The military was not keen on the treaty option, but it must have been clear that Kennedy was leaning in that direction. The head of Strategic Air Command, Curtis LeMay, bluntly told Kennedy that he wanted a 100-megaton bomb but would accept the assurances of the AEC that a 50-megaton bomb could be developed without testing, and that he understood it would be to the nation’s “political disadvantage” if they did not ratify the treaty.
Secretary of Defense McNamara would be called before Congress to defend the military implications of the treaty before they ratified it. He was emphatically in favor of it—the only area where the United States was not ahead of the Soviets in testing was “very high-yield” weapons, but he now argued that the United States had “no great interest” in those. It was a return to the public rhetoric that had proliferated after the first announcement of a 100-megaton test by the Soviets: Such weapons were wasteful and ridiculous. Lower-yield weapons, which were still quite powerful (a megaton or two is nothing to sniff at!), could be even more destructive if deployed in quantity. The security gained from a treaty that would not only reduce global fallout but would also guarantee a trend toward lower yields, would be worth anything that could be gained from multi-megaton tests.
But this was not truly the end of an American Tsar Bomba. A key part of the Limited Test Ban Treaty, for the first decade or so after it was signed and ratified, was a provision for “readiness” of testing. Should the Soviets break the treaty, the United States would be ready to immediately begin atmospheric nuclear testing—it wouldn’t be caught off-guard like it was when the Soviets ended the Test Moratorium. The Americans hoped this threat would make the Soviets think twice about breaking the treaty, and they began planning for tests that would shed light on things that were hard to study with underground detonations, like the electromagnetic pulse effect.
Someone wrote on the memo, “My guess is we could go slower on this.” But the test preparations went ahead anyway.
So even while the United States professed to not care about “very high-yield” weapons, it continued to study them well into the Johnson administration. The Department of Defense was secretly convinced that weapons in this range were “significantly superior” when it came to destroying very hard targets, like deep-underground bunkers. The AEC seemed to go along with this, saying it could do underground tests that would elaborate some of the concepts involved (including in the low-megaton range, which would be quite difficult), and that they were trying to establish a “readiness” capability to test 50- to 100-megaton weapons within 90 days of being ordered to by the White House. White House advisor McGeorge Bundy bluntly asked Johnson whether this was a prudent requirement:
Is the requirement for research and development in the very high-yield area sufficiently urgent to justify tests in the megaton range at this time? Do we really need to have a 50-100 [megaton] device ready for test within 90 days if the Limited Test Ban Treaty should be abrogated? When could effects tests using these very high-yield devices actually be conducted since [the Department of Defense] has made no provision to fund these very expensive tests?
Someone wrote on the memo, “My guess is we could go slower on this.” But the test preparations went ahead anyway. The aforementioned Big Test Vehicle (BTV) and Flashback Test Vehicle would be maintained for a decade and used in training exercises, so that if the time came, gigantic-yield warheads could be placed inside them for atmospheric testing.
But the Soviets never broke the Limited Test Ban Treaty, and smaller warheads became the norm. Warheads that could be mounted in multiples and independently targeted on a single missile, or put into submarines, became the core of the arsenal. Large, high-yield weapons would, eventually, be mostly phased out. The dismissal of the uselessness of the Tsar Bomba would become orthodoxy, as even the CIA (eventually) concluded that the Soviets were not going to field such a thing in numbers or try to put superbombs on missiles.
By 1968 the previous interest in high-yield bombs was quickly seeming irrelevant. With the United States bogging down in Vietnam, someone from Sandia suggested filling BTVs with gasoline and dropping them on the Vietnamese, with a blast capability equivalent to 20 tons of TNT. Plans continued to test this idea through 1971. But by 1976, Sandia would, in its own way, celebrate the end of the “very high-yield” weapons era by giving the specialized BTV transporter to NASA, where it would be used to load parachute test vehicles for the Space Shuttle program.
The detonation of the Tsar Bomba did not lead to the immediate abandonment of further atmospheric nuclear tests. Sakharov was despondent that high-yield testing continued in the Soviet Union for another year, and credited this with his final falling-out with the Soviet nuclear complex. But did Tsar Bomba, as has sometimes been claimed by Soviet designers, lead to the Limited Test Ban Treaty? In some ways, yes—the resumption of testing after the Test Moratorium and the obsession with high yields once again brought nuclear contamination to the forefront of the conversation. In other ways, no—the obsession with high-yield nuclear weapons was almost a stumbling block on the way to the treaty. Tsar Bomba has an ambiguous legacy.
Footage from the Tsar Bomba documentary footage released in August 2020, showing photo frames of the detonation examined by Soviet military officers.
Ultimately, high-yield weapons were almost forgotten, re-entering the public consciousness only after the fall of the Soviet Union. It is unclear exactly who started calling the giant bomb the “Tsar Bomba,” a throwback to other impracticably large Russian creations (one source suggests it was Trutnev who proposed the name, when a museum exhibit about Soviet nuclear history was being put together in the early 1990s). In its own day, the bomb didn’t have a consistent moniker. The US press mostly just called it the 50- or 100-megaton bomb, though sometimes they associated it with Khrushchev directly (e.g., the “K-bomb”). Today, Russian sources sometimes call it “Kuzkina mat”—Kuzka’s mother—after a Russian idiom (of obscure origins) that Khrushchev used in 1959 (“We’ll show you Kuzka’s mother!”). Sakharov himself referred to it in his memoirs as simply “the Big Bomb.”
Are the days of the 100-megaton bomb gone for good? One would hope so—though it has been speculated that the Russian Poseidon nuclear-powered drone-torpedo might carry some kind of “very high-yield” charge (reminiscent of a proposal Sakharov made after the successful Tsar Bomba test) as part of its attempt to maintain a credible (and terrifying) deterrence against US ballistic missile defenses. Such a weapon, detonated at sea level, would not only be incredibly devastating to a targeted port and the areas around it, but would, unlike the air-bursted Tsar Bomba, release a swath of deadly radioactive contamination that could cover hundreds of thousands of square miles.
But even if such weapons are now purely relegated to history, we should remember that the decision not to deploy them was not made because the Soviet Union and United States shied away from the shocking megatonnage. It was because massive bombs were harder to use, and something about them symbolized the ridiculousness of the arms race in a way that making thousands of “smaller” weapons (some as big as 20–30 megatons) did not.
The United States did not make 50- to 100-megaton bombs or gigaton bombs, but it made a gigaton arsenal: At its peak in 1960, the US stockpile was some 20,000 megatons, dispersed across tens of thousands of weapons. Even with trends toward miniaturization, it was not until the early 1990s that the US arsenal dropped beneath 5,000 megatons. Today it is probably around 2,000 megatons—more than enough to devastate the planet in a full-scale nuclear war.
The Tsar Bomba is dead; long live the Tsar Bomba. As the United States, Russia, and China seem to be engaged in new arms races in several domains, including unusual and new forms of nuclear delivery vehicles, the Tsar Bomba is a potent example of how nationalism, fear, and high-technology can combine in a fashion that is ultimately dangerous, wasteful, and pointless. “Very high-yield” nuclear weapons weren’t necessary for deterrence, and they were explored at the expense of not only other weapons systems, but also the multitude of other things that nations could spend their wealth and resources on. They didn’t bring safety or security.
Alex Wellerstein is an Associate Professor and Director of the Science and Technology Studies program at the Stevens Institute of Technology. His first book, Restricted Data: The History of Nuclear Secrecy in the United States, was published by the University of Chicago Press in April 2021.
 Vladimir Afanasyev, quoted in Vladimir Suvorov, Strana Limoniya (Soviet Russia Press, 1989), 124-125.
 The US would announce that the yield was potentially as high as 57 or 58 megatons, and the Soviets would at times publicly embrace that higher estimate as well, with Khrushchev indicating at times that it was bigger than hoped for. Internally, the Soviets seem to have concluded it was actually “just” 50 megatons. Internally, the CIA guessed it might be as high as 63 megatons — likely just a reflection of threat hype. Central Intelligence Agency, “The Soviet Atomic Energy Program,” National Intelligence Estimate 11-2A-63 (2 July 1963), 1. The difference between 50 and even 63 megatons, as this article indicates, is not as meaningful as it sounds, because of how damage scales with explosive yield. For more discussion of the yield question (and many other interesting details about the test), see Carey Sublette, “Big Ivan, The Tsar Bomb (‘King of Bombs’),” Nuclear Weapon Archive (3 September 2007), who notes pithily: “After the fall of the USSR…. these motivations to continue with inaccurate estimates disappeared.”
 James B. Conant to Vannevar Bush (20 October 1944), quoted in Chuck Hansen, The Swords of Armageddon, 2nd edn., volume II, (Sunnyvale, Calif.: Chukelea Productions, 1995, 2007), 16.
 R.W. Dodson, “Minutes to the 41st Meeting of the General Advisory Committee to the US Atomic Energy Commission,” (July 12–15, 1954). Many differently-redacted versions of this meeting exist, including two in the Nuclear Testing Archive, Las Vegas, NV (documents NV0411974 and NV0073403). The code-names Gnomon and Sundial are visible only on a copy in the Chuck Hansen papers at the National Security Archive at George Washington University.
 A Freedom of Information Act request by the author in 2015 obtained a few reports on Gnomon research at Livermore. By March 1955, there were at least 40 of them. Unfortunately, nearly every word in said reports, except for the date and number, were redacted by the National Nuclear Security Administration. On the testing during Redwing and its cancellation, see in particular B. Sussholtz to G.W. Johnson, “Tsunami Problem,” UCRL-ID-127830 (8 December 1955), which mentions a projected 60-megaton test on page 5.
 Gennady Gorelik with Antonina W. Bouis, The world of Andrei Sakharov: A Russian physicist’s path to freedom (Oxford University Press, 2005), 175-179. See also Alex Wellerstein and Edward Geist, “The secret of the Soviet hydrogen bomb,” Physics Today 70, no. 4 (March 2017), 40-47.
 Veselovskij and Ioilev, 24. It is unclear why they use the term “bifilar,” which means double-threaded, and usually refers to coils or other similar sorts of arrangements where pairs of wires are used.
 Both quoted in Adamski, Smirnov, and Trutnev, 150. Some paraphrasing has been done to render their commentary more clear in English.
 The literal translation is “pure” hydrogen bomb, but in context they are referring to what would be considered a “clean” bomb in the Western context: a nuclear weapon with a very small fraction of its total yield derived from nuclear fission, as opposed to nuclear fusion.
 White House Release about the 50-megaton detonation (30 October 1961), Nuclear Testing Archive, NV0176747.
 Ernest May, John D. Steinbruner, and Thomas W. Wolfe, “History of the Strategic Arms Competition, 1945-1972, Part 1,” (Office of the Secretary of Defense, History Office, March 1981), 204; Austin Betts to Glenn Seaborg (24 July 1963), Nuclear Test Archive, NV0178602; Report to the President by the Secretary of State, the Secretary of Defense, and the Chairman, Atomic Energy Commission (ca. August 1957), GaleNet Declassified Documents Online, DDRS-267715.
 It is unclear whether this is the same test as the aforementioned GNOMON device.
 US Strategic Air Command, “History of the Strategic Air Command,” 87.
 George F. Lemmer, “The Air Force and Strategic Deterrence,” USAF Historical Division Liaison Office (December 1967), GaleNet Declassified Documents Online, DDRS-309839.
 “B-52 has 50-megaton load, lawmaker says,” Los Angeles Times (27 October 1961), 21; “It’s official: B-52s pack 2 25-megaton bombs,” Boston Globe (30 October 1961), 7; U.S. Department of Energy Office of Declassification, “Restricted Data Declassification Decisions, 1946 to the Present (RDD-8),” (1 January 2002), entry V.F.3.e; DCI Briefing to Joint Chiefs of Staff (30 July 1963): “The US has stockpiled bombs of 9 MT and 23 MT.”
 Willam Ogle, “An Account of the Return to Nuclear Weapons Testing by the United States After the Test Moratorium, 1958-1961,” (October 1985), Nuclear Testing Archive, NV0092202.
 Glenn Seaborg to John F. Kennedy (18 October 1961), Nuclear Testing Archive, NV0915104.
 Ogle, “An Account of the Return to Nuclear Weapons Testing,”; Glenn Seaborg journal entry (21 October 1961), Nuclear Testing Archive, NV0900560; Col. Clyde Gasser to Lt. Gen. R.C. Wilson, “Priority of Nuclear Weapons Tests of Primary Interest to the Air Force” (25 October 1961), Document 37 in William Burr and Hector L. Montford, eds., “The Making of the Limited Test Ban Treaty, 1958-1963,” Electronic Briefing Book no. 94 (8 August 2003).
 Virgil Elbert to D.H. Cotter, et al. (ca. March 1962), Digital National Security Archive, George Washington University, document NH-00081.
 Glenn Seaborg to Robert McNamara (13 December 1962). Several differently-redacted versions of this fascinating memo exist, including two in the Nuclear Testing Archive (NV0915114 and NV0058335), and one in the GaleNet Declassified Documents Online (DDRS-262940). I am grateful to Carey Sublette for the suggestion about the spherical nature of the RIPPLE secondary and its impact on the ballistic shape of a high-yield RIPPLE warhead. Sublette’s 2007 page on the Tsar Bomba, cited earlier, was also of good use in starting these investigations.
 Roswell Gilpatric to Glenn Seaborg (6 March 1963), Nuclear Testing Archive, NV0915160, with attachment (NV091561).
 Seaborg to Gilpatric (17 April 1963), Nuclear Testing Archive, NV0176741.
 Austin Betts to Glenn Seaborg, et al. (29 May 1963), Nuclear Testing Archive, NV0178604.
 Glenn Seaborg journal entry (ca. February 1964),Journal of Glenn T. Seaborg: November 23, 1963–February 28, 1964 (Lawrence Berkeley Laboratory, 1989), 430-431. I would like to thank Scott Lowther for bringing Flashback to my attention in 2018 as a mystery to be solved.
 William Foster to Glenn Seaborg (20 May 1963), Nuclear Testing Archive, NV0176739.
 Glenn Seaborg to Lawrence Hafstad (28 March 1964), Nuclear Testing Archive, NV0073694.
Astronomers have detected a record number of gravitational waves, in a discovery they say will shed light on the evolution of the universe, and the life and death of stars.
An international team of scientists have made 35 new observations of gravitational waves, which brings the total number of detections since 2015 to 90.
Gravitational waves are ripples in the fabric of spacetime, created by massive cosmic events – such as pairs of black holes smashing together – up to billions of light years away.
Waves from these cataclysmic collisions were detected by the Laser Interferometer Gravitational-Wave Observatory (Ligo) observatory in the US and the Virgo instrument in Italy between November 2019 and March 2020.
The first detection of gravitational waves, announced in 2016, confirmed a prediction Albert Einstein made a century earlier based on his general theory of relativity.
Monash University researcher Shanika Galaudage, a collaborator in the Australian branch of the project known as OzGrav, described gravitational waves as a game-changing “new window into the universe”.
“Gravitational waves are not [electromagnetic] light,” Galaudage said. “We can see things that are invisible, such as binary black hole mergers.”
Of the 35 new detections, 32 likely resulted from pairs of black holes merging.
Notable discoveries included two massive pairs of black holes orbiting each other – one pair that was 145 times as heavy as the mass of the sun, and the other 112 times. The scientists also discovered a “light” pair of black holes with a combined mass only 18 times that of the sun.Two of the 35 detections are believed to have originated from a neutron star merging with a black hole.
Neutron stars are small, incredibly dense objects: although they weigh around 1.4 times the mass of the sun, they are city-sized, with a radius of approximately 15km, said research collaborator Prof Susan Scott, of the Australian National University.
Scott said the detections were helping scientists understand both the evolution of the universe and also the nature of stellar objects.
“Eventually as we make the detectors even more sensitive, we’ll be able to see all the binary black hole pairs coming together throughout the whole universe,” Scott said.
“Neutron stars when they collide – they don’t create as strong gravitational waves as the black holes because they’re not as dense, and therefore we can’t see them out as far.”
In future, astronomers may also be able to detect gravitational waves from stars as they become supernovae. “This would help us to understand the process of stars when they finish their life cycle and run out of fuel and blow up and then collapse,” Scott said.
Analysing certain properties of the mergers allowed scientists to determine how they were formed, Galaudage said.
“By looking at how a black hole is spinning, for example – how fast it’s spinning, versus … which way it’s pointed – can tell us more about how it came to be: whether these black holes lived their lives apart and met at some point or whether they were stars to begin with, and then collapsed down [separately] to form black holes, and then went on to merge and produce these gravitational waves,” she said.
Some of the new detections are still mysterious. The researchers believe the 35th event could be either a pair of black holes, or a merger between a black hole and a neutron star.
The lighter object in this event had a mass greater than would be usual for a neutron star, but smaller than that of a black hole. “We’re seeing features … that we cannot explain yet,” Galaudage said.
China Muslims: Xinjiang schools used to separate children from families
By John Sudworth
BBC News, Xinjiang
China is deliberately separating Muslim children from their families, faith and language in its far western region of Xinjiang, according to new research.
At the same time as hundreds of thousands of adults are being detained in giant camps, a rapid, large-scale campaign to build boarding schools is under way.
Based on publicly available documents, and backed up by dozens of interviews with family members overseas, the BBC has gathered some of the most comprehensive evidence to date about what is happening to children in the region.
Records show that in one township alone more than 400 children have lost not just one but both parents to some form of internment, either in the camps or in prison.
Formal assessments are carried out to determine whether the children are in need of “centralised care”.
Alongside the efforts to transform the identity of Xinjiang’s adults, the evidence points to a parallel campaign to systematically remove children from their roots.
China’s tight surveillance and control in Xinjiang, where foreign journalists are followed 24 hours a day, make it impossible to gather testimony there. But it can be found in Turkey.
In a large hall in Istanbul, dozens of people queue to tell their stories, many of them clutching photographs of children, all now missing back home in Xinjiang.
“I don’t know who is looking after them,” one mother says, pointing to a picture of her three young daughters, “there is no contact at all.”
Another mother, holding a photo of three sons and a daughter, wipes away her tears. “I heard that they’ve been taken to an orphanage,” she says.
In 60 separate interviews, in wave after wave of anxious, grief-ridden testimony, parents and other relatives give details of the disappearance in Xinjiang of more than 100 children.
They are all Uighurs – members of Xinjiang’s largest, predominantly Muslim ethnic group that has long had ties of language and faith to Turkey. Thousands have come to study or to do business, to visit family, or to escape China’s birth control limits and the increasing religious repression.
But over the past three years, they have found themselves trapped after China began detaining hundreds of thousands of Uighurs and other minorities in giant camps.
The Chinese authorities say the Uighurs are being educated in “vocational training centres” in order to combat violent religious extremism. But evidence shows that many are being detained for simply expressing their faith – praying or wearing a veil – or for having overseas connections to places like Turkey.
For these Uighurs, going back means almost certain detention. Phone contact has been severed – even speaking to relatives overseas is now too dangerous for those in Xinjiang.
With his wife detained back home, one father tells me he fears some of his eight children may now be in the care of the Chinese state.
“I think they’ve been taken to child education camps,” he says.
New research commissioned by the BBC sheds light on what is really happening to these children and many thousands of others.
Campuses have been enlarged, new dormitories built and capacity increased on a massive scale. Significantly, the state has been growing its ability to care full-time for large numbers of children at precisely the same time as it has been building the detention camps.
And it appears to be targeted at precisely the same ethnic groups.
In just one year, 2017, the total number of children enrolled in kindergartens in Xinjiang increased by more than half a million. And Uighur and other Muslim minority children, government figures show, made up more than 90% of that increase.
As a result, Xinjiang’s pre-school enrolment level has gone from below the national average to the highest in China by far.
In the south of Xinjiang alone, an area with the highest concentration of Uighur populations, the authorities have spent an eye watering $1.2bn on the building and upgrading of kindergartens.
Mr Zenz’s analysis suggests that this construction boom has included the addition of large amounts of dormitory space.
Xinjiang’s education expansion is driven, it appears, by the same ethos as underlies the mass incarceration of adults. And it is clearly affecting almost all Uighur and other minority children, whether their parents are in the camps or not.
In 2018 work began on a site for two new boarding schools in Xinjiang’s southern city of Yecheng (known as Kargilik in Uighur).
Yecheng County Middle Schools 10 and 11
Dragging the slider reveals the pace of construction – the two middle schools, separated by a shared sports field, are each three times larger than the national average and were built in little more than a year.
In April last year, the county authorities relocated 2,000 children from the surrounding villages into yet another giant boarding middle school, Yecheng County Number 4.
Government propaganda extols the virtues of boarding schools as helping to “maintain social stability and peace” with the “school taking the place of the parents.” And Mr Zenz suggests there is a deeper purpose.
“Boarding schools provide the ideal context for a sustained cultural re-engineering of minority societies,” he argues.
Just as with the camps, his research shows that there is now a concerted drive to all but eliminate the use of Uighur and other local languages from school premises. Individual school regulations outline strict, points-based punishments for both students and teachers if they speak anything other than Chinese while in school.
And this aligns with other official statements claiming that Xinjiang has already achieved full Chinese language teaching in all of its schools.
Speaking to the BBC, Xu Guixiang, a senior official with Xinjiang’s Propaganda Department, denies that the state is having to care for large numbers of children left parentless as a result.
“If all family members have been sent to vocational training then that family must have a severe problem,” he says, laughing. “I’ve never seen such a case.”
But perhaps the most significant part of Mr Zenz’s work is his evidence that shows that the children of detainees are indeed being channelled into the boarding school system in large numbers.
There are the detailed forms used by local authorities to log the situations of children with parents in vocational training or in prison, and to determine whether they need centralised care.
Mr Zenz found one government document that details various subsidies available to “needy groups”, including those families where “both a husband and a wife are in vocational training”. And a directive issued to education bureaus by the city of Kashgar that mandates them to look after the needs of students with parents in the camps as a matter of urgency.
Schools should “strengthen psychological counselling”, the directive says, and “strengthen students’ thought education” – a phrase that finds echoes in the camps holding their parents.
It is clear that the effect of the mass internments on children is now viewed as a significant societal issue, and that some effort is going into dealing with it, although it is not something the authorities are keen to publicise.
Some of the relevant government documents appear to have been deliberately hidden from search engines by using obscure symbols in place of the term “vocational training”. That said, in some instances the adult detention camps have kindergartens built close by, and, when visiting, Chinese state media reporters have extolled their virtues.
These boarding schools, they say, allow minority children to learn “better life habits” and better personal hygiene than they would at home. Some children have begun referring to their teachers as “mummy”.
We telephoned a number of local Education Bureaus in Xinjiang to try to find out about the official policy in such cases. Most refused to speak to us, but some gave brief insights into the system.
We asked one official what happens to the children of those parents who have been taken to the camps.
“They’re in boarding schools,” she replied. “We provide accommodation, food and clothes… and we’ve been told by the senior level that we must look after them well.”
In the hall in Istanbul, as the stories of broken families come tumbling out, there is raw despair and deep resentment too.
“Thousands of innocent children are being separated from their parents and we are giving our testimonies constantly,” one mother tells me. “Why does the world keep silent when knowing these facts?”
Back in Xinjiang, the research shows that all children now find themselves in schools that are secured with “hard isolation closed management measures.” Many of the schools bristle with full-coverage surveillance systems, perimeter alarms and 10,000 Volt electric fences, with some school security spending surpassing that of the camps.
The policy was issued in early 2017, at a time when the detentions began to be dramatically stepped up. Was the state, Mr Zenz wonders, seeking to pre-empt any possibility on the part of Uighur parents to forcibly recover their children?
“I think the evidence for systematically keeping parents and children apart is a clear indication that Xinjiang’s government is attempting to raise a new generation cut off from original roots, religious beliefs and their own language,” he tells me.
“I believe the evidence points to what we must call cultural genocide.”
Chinese authorities claim the Uighurs are being educated in “vocational training centres” designed to combat extremism.
But evidence suggests that many are being detained for simply expressing their faith – praying or wearing a veil – or for having overseas connections to places like Turkey.
More than a million people are thought to be held within the system.
After parents are detained, formal assessments are then carried out to determine whether the children need “centralised care”.
One local official told the BBC that children whose parents had been detained in camps were sent to boarding schools.
“We provide accommodation, food and clothes… and we’ve been told by the senior level that we must look after them well,” she said.
But Dr Adrian Zenz, who carried out the research commissioned by the BBC, said boarding schools “provide the ideal context for a sustained cultural re-engineering of minority societies.”
“I think the evidence for systematically keeping parents and children apart is a clear indication that Xinjiang’s government is attempting to raise a new generation cut off from original roots, religious beliefs and their own language,” he said.
Dozens of Uighur parents living in Turkey spoke to the BBC about their desire to be united with their missing children.
“I don’t know who is looking after them… there is no contact at all,” one mother said.
Thousands of Uighurs have moved to Turkey to do business, to visit family, or to escape China’s birth control limits and what they call religious repression.
Many stayed after China began detaining hundreds of thousands of Uighurs over the past three years.
Mr Liu, however, described the parents who spoke to the BBC as “anti-government people”.
“You cannot expect a good word [from them] about the government,” he said. “If they want to be with their children they can come back.”
Searching for truth in China’s Uighur ‘re-education’ camps
By John Sudworth
BBC News, Xinjiang
The Chinese region of Xinjiang is home to millions of ethnic Muslim Uighurs who have lived there for decades. Rights groups say hundreds of thousands have been detained in camps without trial, but China argues they voluntarily attend centres which combat “extremism”. The BBC went inside one of them.
I’d been to the camps before.
But the closest I’d managed to get on previous visits were snatched glimpses of the barbed wire and watchtowers from a passing car, while the plainclothes police officers tailing us tried to stop us getting any closer.
Now I was being invited inside.
The risks of accepting were obvious. We were being taken into places that appeared to have been carefully spruced up – with satellite images revealing that much of the security infrastructure had recently been removed.
And one by one the people we spoke to inside, some of them visibly nervous, told us similar stories.
All of them members of Xinjiang’s largest, mainly Muslim ethnic group – the Uighurs – they said they’d been “infected by extremism” and that they’d volunteered to have their “thoughts transformed”.
This was China’s narrative in the mouths of people selected for us, and for whom any cross-examination might pose a serious risk.
What might be the consequences if they did let something slip? How could we safely separate the propaganda from the reality?
Radicalised and reborn
There are plenty of precedents for this kind of reporting dilemma.
There was the heavily managed 2004 press tour of the US-run Abu Ghraib prison in Iraq, in the wake of the abuse scandal, with reporters herded away from detainees clamouring to have their voices heard, some while waving their prosthetic legs.
In Xinjiang though, there is one big difference. The authorities grant access not only to show that the conditions inside the facilities are good, they also want to prove that they are not prisons at all.
We were shown adults seated in rows at school desks in brightly lit classrooms, chanting in unison while learning Chinese.
Some performed highly staged and choreographed music and dance routines for us, wearing traditional ethnic costumes, whirling around their desks, smiles fixed in place.
And what was quite clear was that the Chinese officials accompanying us believed wholeheartedly in the narrative on display, some almost moved to tears as they looked on.
These people, we were urged to recognise, were reborn. Once dangerously radicalised and full of hatred for the Chinese government, they were now safely back on the road to reform thanks to the timely, benevolent intervention of that same government.
The West could learn a lot from this was the message.
Referring to the date the re-education policy began, one senior official looked me sternly in the eye.
“There has not been a single terror attack in Xinjiang in 32 months,” he said. “This is our patriotic duty.”
‘Oh my heart don’t break’
But in accepting the access, our job was to try to peer beneath the official messaging and hold it up to as much scrutiny as we could.
There were the bits of graffiti we filmed, written in Uighur, that we later had translated.
“Oh my heart don’t break,” read one. Another in Chinese said simply: “Step by step.”
There were the answers, in extended interviews with the officials, that revealed much about the nature of the system.
Those in it were “almost criminals,” they said, viewed as a threat not because they’d committed a crime, but because they might have the potential to do so.
And there was the admission that, once identified as having extremist tendencies, they were given a choice – but not much of one.
The option was “of choosing between a judicial hearing or education in the de-extremification facilities”.
“Most people choose to study,” we were told. Little wonder, given the odds of a fair trial.
And we know, from other sources, that the definition of extremism is now drawn very widely indeed – having a long beard for example, or simply contacting relatives overseas.
We saw the dormitories in which these “extremists” slept, up to 10 per room, in bunk beds and with a toilet at one end, shielded with only a thin sheet of fabric.
And then there was the cautious questioning that revealed much, not in what they could say, but what they couldn’t.
China Uighurs: All you need to know on Muslim ‘crackdown’
By Roland Hughes
China is facing growing criticism over its persecution of some Muslim minority groups, huge numbers of whom are allegedly being held in internment camps.
In August 2018, a UN committee heard that up to one million Uighur Muslims and other Muslim groups could be being detained in the western Xinjiang region, where they’re said to be undergoing “re-education” programmes.
The claims were made by rights groups, but China denies the allegations. At the same time, there’s growing evidence of oppressive surveillance against people living in Xinjiang.
We’ve developed this new format to try to explain the story to you better.
What’s happened to the vanished Uighurs of Xinjiang?
By John Sudworth
China is accused of locking up hundreds of thousands of Muslims without trial in its western region of Xinjiang.
The government denies the claims, saying people willingly attend special “vocational schools” which combat “terrorism and religious extremism”.
Now a BBC investigation has found important new evidence of the reality.
Detention in the desert
On 12 July 2015 a satellite swung over the rolling deserts and oasis cities of China’s vast far west.
One of the images it captured that day just shows a patch of empty, untouched, ashen-grey sand.
It seems an unlikely place to start an investigation into one of the most pressing human rights concerns of our age.
But less than three years later, on 22 April 2018, a satellite photo of that same piece of desert showed something new.
A massive, highly secure compound had materialised.
It is enclosed with a 2km-long exterior wall punctuated by 16 guard towers.
The first reports that China was operating a system of internment camps for Muslims in Xinjiang began to emerge last year.
The satellite photograph was discovered by researchers looking for evidence of that system on the global mapping software, Google Earth.
It places the site just outside the small town of Dabancheng, about an hour’s drive from the provincial capital, Urumqi.
To try to avoid the suffocating police scrutiny that awaits every visiting journalist, we land at Urumqi airport in the early hours of the morning.
But by the time we arrive in Dabancheng we’re being followed by at least five cars, containing an assortment of uniformed and plain-clothes police officers and government officials.
It’s already clear that our plan to visit a dozen suspected camps over the course of the next few days is not going to be easy.
As we drive up the wide approach road we know that sooner or later the convoy behind is going to try to stop us.
While still a few hundred metres away, we see something unexpected.
The wide expanse of dusty ground, shown on the satellite image to the east of the site, is empty no more.
In its place, a huge extension project is taking shape.
The site at Dabancheng seen from the road
Like a mini-city sprouting from the desert and bristling with cranes, are row upon row of giant, grey buildings – all of them four storeys high.
With our cameras rolling we try to capture the extent of the construction, but before we can go much further one of the police cars swings into action.
Our car is stopped – we’re told to turn off the cameras and to leave.
But we’ve discovered something of significance – a huge amount of extra activity that has so far gone unnoticed by the outside world.
In remote parts of the world, Google Earth images can take months or years to update.
Other public sources of satellite photography however – like the European Space Agency’s Sentinel database – provide much more frequent images, although they’re of a much lower resolution.
It is here that we find what we are looking for.
An October 2018 Sentinel image shows just how much the site has grown compared with what we’d expected to see.
What we suspected to be a big internment camp, now looks like an enormous one.
And it is just one of many similar, large prison-type structures that have been built across Xinjiang in the past few years.
Before our attempt to visit the site, we’d stopped in the centre of Dabancheng.
It was impossible to speak openly to anyone – minders lurked menacingly close by and would aggressively debrief anyone who even exchanged a greeting with us.
Instead, we telephoned random numbers in the town.
What was this large complex with its 16 watchtowers that the authorities were so desperate to stop us filming?
“It’s a re-education school,” one hotelier told us.
“Yes, that’s a re-education school,” another shopkeeper agreed.
“There are tens of thousands of people there now. They have some problems with their thoughts.”
This giant facility would of course fit no objective definition of a school.
In Xinjiang “going to school” has come to take on a meaning all of its own.
“I have deeply understood my mistakes”
A still from a Chinese state TV report on the Uighur “schools”
China has consistently denied that it is locking up Muslims without trial.
But a euphemism for the camps has long existed – education.
Almost certainly as a response to the mounting international criticism, the authorities have begun to double down on this description, with a full-on propaganda drive.
State-run TV has been showing glossy reports, full of clean classrooms and grateful students, apparently willingly submitting themselves to the coursework.
There is no mention of the grounds on which the students have been chosen for this “study” or how long the courses last.
But there are clues.
The interviews sound more like confessions.
“I have deeply understood my own mistakes,” one man tells the camera, vowing to be a good citizen “after I get home”.
The main purpose of these facilities, we’re told, is to combat extremism, through a mixture of legal theory, work skills and Chinese language training.
That last item shows that whatever you want to call them – schools or camps – the intended target is the same.
The facilities are exclusively for Xinjiang’s Muslim minorities, many of whom do not speak Chinese as their mother tongue.
The video suggests the school is operating a dress code – not a single one of the female students is wearing a headscarf.
There are more than 10 million Uighurs in Xinjiang.
They speak a Turkic language and resemble the peoples of Central Asia at least as much as they do China’s majority population, the Han Chinese.
The southern city of Kashgar, it is often pointed out, is geographically closer to Baghdad than it is to Beijing – and it sometimes feels culturally closer too.
And with a history of rebellion and resistance to Chinese rule, the relationship between the Uighurs and their modern-day political masters has long been as fraught as it is distant.
Before Communist rule, Xinjiang occasionally slipped from China’s grip with brief periods of independence. Ever since, it has constantly tested that grip with sporadic outbreaks of protest and violence.
The mineral wealth – in particular oil and gas – of a region almost five times the size of Germany has brought huge levels of Chinese investment, rapid economic growth and large waves of Han Chinese settlers.
Resentment among Uighurs over the perceived uneven distribution of the proceeds of that growth has simmered.
In response to such criticisms, the Chinese authorities point to rising living standards for Xinjiang’s residents.
But in the past decade or so, hundreds of lives have been lost to a mixture of riots, inter-community violence, premeditated attacks and the police response.
October 2013: Tiananmen Square sealed off after a car attack which killed two people
In 2013, an attack on pedestrians in Beijing’s Tiananmen Square, which claimed two lives as well as the three Uighur occupants of the car, marked a significant moment.
Although relatively small in terms of fatalities it rattled the foundations of the Chinese state.
March 2014: Police in Kunming on patrol after the killing of 31 people
The following year, 31 people were slaughtered by knife-wielding Uighur attackers at a train station in the Chinese city of Kunming, more than 2000km away from Xinjiang.
Over the past four years, Xinjiang has been the target of some of the most restrictive and comprehensive security measures ever deployed by a state against its own people.
These include the large-scale use of technology – facial recognition cameras, monitoring devices that read the content of mobile phones and the mass collection of biometric data.
Harsh new legal penalties have been introduced to curtail Islamic identity and practice – banning, among other things, long beards and headscarves, the religious instruction of children, and even Islamic-sounding names.
The policies appear to mark a fundamental shift in official thinking – separatism is no longer framed as a problem of a few isolated individuals, but as a problem inherent within Uighur culture and Islam in general.
It coincides with a tightening grip on society under President Xi Jinping, in which loyalties to family and faith must be subordinate to the only one that matters – loyalty to the Communist Party.
The Uighurs’ unique identity makes them a target for suspicion.
That view has been reinforced by credible reports that hundreds have travelled to Syria to fight with various militant groups.
Uighurs are now subject to ethnic profiling at thousands of pedestrian and vehicle checkpoints while Han Chinese residents are often waved through.
A police checkpoint in Kashgar, March 2017
They face severe travel restrictions, both within Xinjiang and beyond, with an edict forcing residents to surrender all passports to the police for “safe keeping”.
Uighur government officials are prohibited from practising Islam, from attending mosques or from fasting during Ramadan.
A Chinese flag flies above a closed mosque in the Xinjiang city of Kashgar
Given all this, it is perhaps not that surprising that China has introduced another older and blunter solution to the perceived disloyalty of many of its Uighur citizens.
Despite the government’s denials, the most compelling evidence for the existence of the internment camps comes from a trove of information from the authorities themselves.
Pages of local government tendering documents inviting potential contractors and suppliers to bid for the building projects have been discovered online by the German-based academic, Adrian Zenz.
They provide details about the construction or conversion of dozens of separate facilities across Xinjiang.
In many cases the tenders call for the installation of comprehensive security features, such as watchtowers, razor wire, surveillance systems, and guardrooms.
Cross-referencing this information with other media sources, Zenz suggests that at least several hundred thousand and possibly over a million Uighurs and other Muslim minorities could have been interned for re-education.
The documents, of course, never refer to the facilities as internment camps, but as education centres, or in a more accurate translation, “re-education centres”.
One of them almost certainly relates to the giant site we visited – a July 2017 tender for the installation of a heating system in a “transformation through education school” somewhere in the district of Dabancheng.
In these euphemisms, and in the mundane measurements and quantities described, there is the unmistakable substance of a rapidly expanding network of mass confinement.
“They want to delete Uighur identity”
In 2002, Reyila Abulaiti travelled from Xinjiang to the UK to study.
She met and married a British man, took British citizenship and started a family.
Last year, her mother came for her usual summer visit, spending time with her daughter and grandson and doing a bit of London sightseeing.
Xiamuxinuer Pida, 66, is a well-educated former-engineer with a long service record at a Chinese state company.
She flew back to Xinjiang on 2 June.
Having not heard from her, Reyila called to check she’d got home OK.
The conversation was brief and terrifying.
“She told me that the police were searching the house,” Reyila remembers.
It was Reyila who appeared to be the target of the investigation.
She needed to send copies of her documents, her mother said – proof of UK address, a copy of her British passport, her UK telephone numbers and information about her university course.
And then, after asking her to send them via a Chinese mobile chat service, Xiamuxinuer said something that sent a chill down Reyila’s spine.
“Don’t call me again,” her mother told her. “Don’t call me ever.”
It was the last time her daughter would hear her voice.
She believes she has been in a camp ever since.
“My mum has been detained for no reason,” she says. “As far as I know, the Chinese government wants to delete Uighur identity from the world.”
The BBC has conducted lengthy interviews with eight Uighurs living overseas.
Their testimonies are remarkably consistent, providing evidence of the conditions and routines inside the camps and the broad basis on which people are detained.
Mainstream religious activity, the mildest dissent and any link with Uighurs living in foreign countries appear to be enough to sweep people into the system.
Ablet Tursun Tohti
Each morning, when 29-year-old Ablet Tursun Tohti was woken an hour before sunrise, he and his fellow detainees had one minute to get to the exercise yard.
After lining up, they were made to run.
“There was a special room to punish those who didn’t run fast enough,” Ablet says. “There were two men there, one to beat with a belt, the other just to kick.”
The exercise yard can clearly be seen on the satellite photo of the camp where he says he was held, in the oasis town of Hotan in southern Xinjiang.
“We sang the song called ‘Without the Communist Party There Can Be No New China,’” Ablet says.
“And they taught us laws. If you couldn’t recite them in the correct way, you’d be beaten.”
A 2018 satellite image showing a camp in Hotan where Ablet says he was detained
He was there for a month in late 2015 and, in some ways, he is one of the lucky ones.
In the early days of the internment camps, the lengths of the re-education “courses” appear to have been shorter.
And since there has now been a mass recall of passports, Ablet was one of the last Uighurs able to leave China.
He has sought refuge in Turkey, a country with a sizeable Uighur diaspora because of strong cultural and linguistic links.
Ablet tells me that his 74-year-old father and eight of his siblings are in the camps. “There is no-one left outside,” he says.
Abdusalam Muhemet, 41, is also now living in Turkey.
He was detained by the police in Xinjiang in 2014 for reciting an Islamic verse at a funeral.
They eventually decided not to charge him, he says, but he still wasn’t free.
“They told me I needed to be educated,” he explains.
The facility he found himself in did not look like a school.
On the satellite photo, you can make out the guard towers and the double perimeter fencing of the Han’airike Legal Education Training Centre.
The rolls of razor wire can be identified from the shadows they cast under the harsh desert sun.
He describes the same routine of exercise, bullying and brainwashing.
Satellite image of the site in Hotan where Abdusalam says he was held
Twenty-five-year-old Ali, not his real name, is one of those too scared to talk openly.
In 2015 he says he ended up in a camp after the police found a picture of woman wearing a niqab, a face veil, on his mobile phone.
“One old lady was there for having made a pilgrimage to Mecca,” he tells me, “and an old man for not paying his water bill on time.”
Ali (not his real name) is unwilling to be identified
During one of the forced exercise sessions an official’s car entered the camp and the gate was briefly left open.
“Suddenly, a small child ran in towards his mother who was running with us.
“She went towards her child, embraced him and started crying.
“Then a policeman grabbed the woman by her hair and dragged the small child out of the camp.”
In place of clean surroundings shown on state TV, a very different picture emerges.
“The doors of our dormitories were locked at night,” Ablet says. But there were no toilets inside, they just gave us a bowl.”
There is no way of independently verifying these accounts.
We asked the Chinese government about the allegations of abuse but have received no reply.
For Uighurs outside Xinjiang news has almost completely dried up.
Fear breeds silence.
Reports of people being deleted from family chat groups, or told never to call again, are now commonplace.
Two of the things most central to Uighur culture – faith and family – are being systematically broken.
As a result of the detention of whole extended families, there are reports that many children are being placed in state orphanages.
Bilkiz Hibibullah arrived in Turkey in 2016 with five of her children.
Her youngest daughter, Sekine Hasan, who by now would be three and a half years old, stayed in Xinjiang with Bilkiz’s husband.
She did not yet have a passport and the plan was that, when she got one, the family would reunite in Istanbul.
She never got that passport.
Bilkiz’s daughter Sekine, whom she has not seen for more than two years
Bilkiz believes her husband was detained on 20 March last year.
She has since lost contact with the rest of her family and now has no idea where her daughter is.
“In the middle of the night, after my other children have gone to bed, I cry a lot,” she says.
“There is nothing more miserable than not knowing where your daughter is, if she is alive or dead.
“If she could hear me now, I’d say nothing but sorry.”
The view from above
Satellite image of site in Hotan enhanced by GMV
Using only publicly available, open-source satellite data, it’s possible to shed light on Xinjiang’s dark secret.
GMV is a multinational aerospace company with experience of monitoring infrastructure from space on behalf of organisations like the European Space Agency and the European Commission.
Their analysts went through a list of 101 facilities located across Xinjiang – drawn up from the various media reports and academic research about the re-education camp system.
One by one, they measured the growth of new sites and the expansion of existing ones.
They identified and compared common features such as watchtowers and security fencing – the kind of things needed to monitor and control the movement of people.
And they categorised the likelihood of each site actually being a security facility, placing 44 of them in the high or very high category.
Then they plotted the first detection by satellite of each of those 44 facilities over time.
Images show the extent of the building work that has taken place at part of the camp where Abdusalem Muhemet was held.
GMV cannot say what the sites are being used for. But it is clear that over the past few years China has been building a lot of new security facilities, at remarkable and increasing speed.
It is likely to be an underestimate of the true picture.
There is a striking conclusion – the recent trend is towards larger facilities.
The number of new construction projects this year has fallen when compared with 2017.
However, in terms of overall surface area of the facilities being built, there is more this year than last.
GMV calculates that, from this set of 44 sites alone, the surface area of secure facilities in Xinjiang has expanded by some 440 hectares since 2003.
This measurement refers to the whole site within the external security walls, not just the buildings.
But 440 hectares represents a lot of additional space.
For context, a 14-hectare site within the city of Los Angeles – containing the Twin Towers Correctional Facility and the Men’s Central Jail – holds a combined total of almost 7,000 prisoners.
Twin Towers Correctional Facility, Los Angeles
We took one of GMV’s findings – the increase in building size at the facility in Dabancheng – and showed it to a team with long experience in prison design at the Australian-based Guymer Bailey Architects.
Using the measurements from the satellite images they calculated that, at an absolute minimum, the facility could provide space for about 11,000 detainees.
Even that minimum estimate would place it alongside some of the biggest prisons in the world.
Riker’s Island in New York, the largest in the US, has space for 10,000 prisoners.
Silivri Prison outside Istanbul, often referred to as Europe’s largest, is designed to house 11,000.
Guymer Bailey Architects (GBA) provided us with this analysis of the possible functions of the various buildings on the site.
Their minimum estimate for occupancy at Dabancheng assumes that the detainees are held only in single rooms.
If dormitories were used instead then the total capacity at Dabancheng would increase dramatically, GBA suggests, with an outer limit of about 130,000.
We also showed the images to Raphael Sperry, an architect and the president of the US-based organisation, Architects/Designers/Planners for Social Responsibility.
“This is a truly massive and bleak detention facility,” he told me.
“It appears as a place designed to pack as many people into as small an area as possible at the lowest construction cost.
“I think 11,000 is likely a significant underestimate… From the available information we can’t tell how the interior is configured or what portion of the buildings is used for detention rather than other functions. Even so, your dormitory estimate of 130,000 people seems, sadly, quite possible.”
The lack of access to the site means there’s no way of independently verifying this analysis.
We asked the authorities in Xinjiang to confirm what the site at Dabancheng is used for but have received no response.
The padlocked door to a house in the city of Kashgar
Not all of Xinjiang’s internment camps are the same.
Some of the secure facilities have not been built from scratch, but are conversions of structures previously used for other purposes, like schools or factories.
These are often smaller and located closer to the centre of towns or cities.
In the northern county of Yining we tried to visit a number of such camps.
We’d seen local government procurement documents for a project to create five “vocational skills education training centres” for the purposes of “safeguarding stability”.
In the centre of town we stop outside a large group of buildings that used to be Yining Number 3 Middle School.
A high, solid blue steel fence now surrounds the site and there’s heavy security on the front gate.
There’s a new watchtower by the playground and another one by what used to be the football pitch.
The pitch is now completely covered by six long steel-roofed buildings.
Outside, visiting family members are queueing up at the security check.
Once again, wherever we go in the town, two or three cars follow us.
When we try to get out to film at one of the camps, this one surrounded by a grey fence, we’re stopped.
The officials, with hands over our camera lenses, tell us that there’s important military training taking place in the area today and we’re instructed to leave.
Outside the former school we see a family, a mother and two children, standing quietly by the fence.
One of the minders tries to stop them from talking but another appears to over-rule him.
“Let them speak,” she says.
I ask them whom they’re visiting.
There’s a pause, before the young boy answers, “My dad”.
The hands cover our lenses once again.
In the city of Kashgar, the once bustling, beating heart of Uighur culture, the narrow streets are eerily quiet. Many of the doors are padlocked shut.
On one, we see a notice instructing people how to respond to questions about where their family members have gone.
“Say they’re being looked after for the good of society and their families,” it says.
The city’s main mosque is more like a museum.
We try to find out when the next prayer time is but no-one seems to be able to tell us.
“I’m just here to deal with tourists,” one official tells us. “I don’t know anything about prayer times.”
In the square, a few beardless old men sit chatting.
We ask them where everyone else is.
One of them gestures to his mouth, holding his lips together to signal that it’s too risky for him to talk to journalists.
But the other whispers: “No-one comes anymore.”
A helmeted policeman, some distance away, is cleaning the mosque steps.
In the silence we can hear the sound of the slop of the water in the bucket and the swish of the mop, echoing across the square.
Chinese tourists are taking photos.
We leave Kashgar on the highway, heading southwest towards an area dotted with Uighur villages and farms, and a great many suspected camps.
We’re being followed as usual but soon we run into an unexpected obstacle.
Ahead of us, the highway appears to have just been closed.
The police officers manning the roadblock tell us that surface of the road has melted in the hot sun.
“It’s not safe to proceed,” they say.
We notice that the other cars are being directed into a car park in a shopping mall, and over the radio, we hear instructions to hold them there “for a while”.
We’re told the wait could be four or five hours and we’re advised to turn around.
We look for alternative routes, but another roadblock always seems to materialise, although the explanations change.
One road is closed for “military training”.
Four times, on four separate roads, we’re turned around before we finally have to admit defeat.
Just a few kilometres away lies another giant camp said to hold around 10,000 people.
System of control
There are Uighurs in positions of authority in Xinjiang.
Many of the government officials and police officers who tailed and stopped us were Uighurs.
If they feel in any way conflicted they cannot say it of course.
A wall poster in Xinjiang reads: “Stability is a blessing, instability is a calamity”
But while the system of profiling and control has been likened by some to Apartheid, clearly that is not entirely accurate.
Many Uighurs do have a stake in the system.
In reality a better parallel can be found in China’s own totalitarian past.
As in the Cultural Revolution, a society is being told that it needs to be taken apart in order to be saved.
Shohrat Zakir, a Uighur and, in theory, the second most powerful politician in the region, suggests the battle has almost been won.
Shohrat Zakir is the chairman of Xinjiang province and an ethnic Uighur
“In the past 21 months, no violent terrorist attacks have occurred and the number of criminal cases, including those endangering public security, has dropped significantly,” he is reported to have told state media.
“Xinjiang is not only beautiful but also safe and stable.”
But when the detainees are released, what then?
The former camp inmates we spoke to were all burning with resentment.
And the world has yet to hear from anyone who has spent time in facilities like Dabancheng, the sinister and secretive facility of such immense proportions.
Our reporting adds to the evidence that the mass re-education programme is internment by any other name – the locking up of many thousands of Muslims without trial or charge, in fact with no access to any legal process at all.
China is already proclaiming it to be a success.
But history holds many troubling precedents about where such a project might end up.
China forcing birth control on Uighurs to suppress population, report says
China is forcing women to be sterilised or fitted with contraceptive devices in Xinjiang in an apparent attempt to limit the population of Muslim Uighurs, according to new research.
The report, by China scholar Adrian Zenz, has prompted international calls for the United Nations to investigate.
China denies the allegations in the report, calling them “baseless”.
The state is already facing widespread criticism for holding Uighurs in detention camps.
It is believed about one million Uighur people have been detained over the past few years in what what the Chinese state defines as “re-education” camps.
China previously denied the existence of the camps, before defending them as a necessary measure against terrorism, following separatist violence in the Xinjiang region.
US Secretary of State Mike Pompeo called on China to “immediately end these horrific practices”.
In a statement, he urged “all nations to join the United States in demanding an end to these dehumanizing abuses”.
China has faced mounting global scrutiny over its treatment of Uighurs in recent years. An investigation by the BBC in 2019 suggested that children in Xinjiang were being systematically separated from their families in an effort to isolate them from their Muslim communities.
What’s in the report?
Mr Zenz’s report was based on a combination of official regional data, policy documents and interviews with ethnic minority women in Xinjiang.
It alleges that Uighur women and other ethnic minorities are being threatened with internment in the camps for refusing to abort pregnancies that exceed birth quotas.
The report also says that Uighur women with more than the legally permitted number of children – but also many women who had not exceeded birth quotas – were involuntarily fitted with intra-uterine devices (IUDs), while others were coerced into receiving sterilisation surgery.
“Since a sweeping crackdown starting in late 2016 transformed Xinjiang into a draconian police state, witness accounts of intrusive state interference into reproductive autonomy have become ubiquitous,” the report says.
According to Mr Zenz’s analysis of the data, natural population growth in Xinjiang has declined dramatically in recent years, with growth rates falling by 84% in the two largest Uighur prefectures between 2015 and 2018 and declining further in 2019.
“This kind of drop is unprecedented, there’s a ruthlessness to it,” Mr Zenz told the Associated Press. “This is part of a wider control campaign to subjugate the Uighurs.”
Former detainees in internment camps in Xinjiang said they were given injections that stopped their periods, or caused unusual bleeding consistent with the effects of birth control drugs.
“Overall, it is likely that Xinjiang authorities are engaging in the mass sterilization of women with three or more children,” the report said.
Politicians call for UN investigation
In a statement on Monday, the Interparliamentary Alliance on China (IPAC), an international cross-party group of politicians including Conservative MP Iain Duncan Smith, Baroness Helena Kennedy QC, and US senator Marco Rubio, called on the UN to “establish an international, impartial, independent investigation into the situation in the Xinjiang region”.
“A body of mounting evidence now exists, alleging mass incarceration, indoctrination, extrajudicial detention, invasive surveillance, forced labor, and the destruction of Uyghur cultural sites, including cemeteries, together with other forms of abuse,” the statement said.
“The world cannot remain silent in the face of unfolding atrocities. Our countries are bound by solemn obligations to prevent and punish any effort to destroy a national, ethnic, racial or religious group ‘in whole or in part’.”
According to a report by the Associated Press published on Monday, women in Xinjiang have faced exorbitant fines and threats of internment for breaching childbearing limits.
Gulnar Omirzakh, a Chinese-born Kazakh, was ordered to get an IUD inserted after having her third child, the AP reported. Two years later, in January 2018, four officials in military camouflage knocked at her door anyway and handed Omirzakh, the penniless wife of a detained vegetable trader, three days to pay a 17,5000 RMB (£2,000) fine for having more than two children.
She was reportedly warned that she would join her husband in an internment camp if she refused to pay.
“God bequeaths children on you. To prevent people from having children is wrong,” Omirzakh told the AP. “They want to destroy us as a people.”
Responding to the report on Monday, China’s foreign ministry said the allegations were “baseless” and showed “ulterior motives”.
Foreign ministry spokesman Zhao Lijian accused media outlets of “cooking up false information on Xinjiang-related issues”.
For decades, under China’s one-child policy, urban minorities were instead allowed two children, or three for rural families. A 2017 policy change, under President Xi Jinping, removed the ethnic distinction, permitting Han Chinese to have the same number of children as minorities, while preserving the urban-rural distinction.
But according to the AP, Han Chinese have been largely spared the abortions, sterilisations, IUD insertions and detentions implemented against minority populations, including the Uighurs.
Mr Zenz’s report characterises the alleged campaign of coercive birth control in Xinjiang as part of a “demographic campaign of genocide” against the Uighurs.
“These findings provide the strongest evidence yet that Beijing’s policies in Xinjiang meet one of the genocide criteria cited in the UN Convention on the Prevention and Punishment of the Crime of Genocide,” he writes.
Uyghur imams targeted in China’s Xinjiang crackdown
By Joel Gunter
China has imprisoned or detained at least 630 imams and other Muslim religious figures since 2014 in its crackdown in the Xinjiang region, according to new research by a Uyghur rights group.
The research, compiled by the Uyghur Human Rights Project and shared with the BBC, also found evidence that 18 clerics had died in detention or shortly after.
Many of the detained clerics faced broad charges like “propagating extremism”, “gathering a crowd to disturb social order”, and “inciting separatism”.
According to testimony from relatives, the real crimes behind these charges are often things like preaching, convening prayer groups, or simply acting as an imam.
The UHRP, working with rights group Justice for All, tracked the fates of 1,046 Muslim clerics — the vast majority of them Uyghurs — using court documents, family testimony and media reports from public and private databases.
While all 1,046 clerics were reportedly detained at some point, in many cases corroborating evidence was not available because of China’s tight control over information in the region.
Among the 630 cases where it was, at least 304 of the clerics appeared to have been sent to prison, as opposed to the network of “re-education” camps most closely associated with China’s mass detention of the Uyghurs.
Where information was available from court documents or testimony about the length of the prison sentence, the punishments reflect the harsh nature of Xinjiang justice: 96% sentenced to at least five years and 26% to 20 years or more, including 14 life sentences.
The database, which drew on research by the Uyghur activist Abduweli Ayup, as well as the Xinjiang Victims Database and Uyghur Transitional Justice Database, is by no means exhaustive — representing only a fraction of the total estimated number of imams in Xinjiang — and much of the data cannot be independently verified.
But the research shines a light on the specific targeting of religious figures in Xinjiang, appearing to support allegations that China is attempting to break the religious traditions of the Uyghurs and assimilate them into Han Chinese culture.
China denies those allegations, saying the purpose of its so-called “re-education” programme in Xinjiang is to stamp out extremism among the Uyghurs and other Muslim minorities.
Tying religion to extremism
China is believed to have detained more than a million Uyghurs and other Muslims in Xinjiang, a large region in north-western China that is home to various ethnically Turkic peoples. The state has been accused of human rights abuses in the region, including forced labour, sterilisation and rape.
Most of those detained in Xinjiang are sent to “re-education” facilities — prison-like camps where they are held for indeterminate periods of time without charge. But others have been given formal prison sentences, the number and severity of which have increased dramatically since 2017.
Publicly available detention or charging documents are rare, but those that do exist demonstrate how the state has worked to tie ordinary religious expression in Xinjiang to extremism or political separatism.
According to the arrest notice for Oken Mahmet, a 51-year-old Kazakh imam from Qaba in Xinjiang, Mahmet was charged with “propagating extremism”. According to testimony collated by the Xinjiang Victims Database, his family says he was arrested for leading Friday prayers and officiating marriages at a mosque.
Mahmet’s initial detention notice says he was detained for “inciting people to violate national laws pertaining to the reading of marriage vows, education, and public governance, as well as making and propagating items related to extremism”. His sentence was reportedly eight to 10 years.
Baqythan Myrzan, a 58-year-old state-approved imam from Hami prefecture, was also arrested for “propagating extremism”. Myrzan was detained in August 2018 and held at a detention facility until May 2019, when he was sentenced to 14 years at the Bingtuan Urumqi Prison. Myrzan’s family says his only crime was going about his duties as an imam.
And the only clues to the alleged offence committed by Abidin Ayup, a prominent scholar and imam from Atush city, were a few lines that appeared in a long court document from a separate case against a Han Chinese official. The official was accused of allowing Ayup’s son to visit him at a hospital detention facility after he was arrested. The court document refers to Ayup, who was 88 when he was detained in 2017, as a “religious extremist”.
Ayup’s niece Maryam Muhammad told the BBC the imam was a “kind, hardworking, charitable man, cultured and knowledgeable, who encouraged young people to study not only religion but all the school subjects”.
Muhammad, who is now in the US, said nearly 60 members of her extended family had been detained since Ayup’s arrest, including her husband and all of the imam’s eight children.
Extremism charges were being issued on a “flimsy legal basis” in Xinjiang for “offences that shouldn’t even qualify as offences”, said Donald Clarke, a professor at George Washington University who specialises in Chinese law.
“Setting to one side for a moment whether you accept ‘propagating extremism’ as a valid charge, the question is do the facts make a plausible case for that charge?” he said. “And the alleged offences we have seen — things like having a beard, not drinking, or travelling abroad — suggest they don’t.”
The real reason imams were being targeted was “because of their ability to bring people together in the community”, said Peter Irwin, senior programme officer at the Uyghur Human Rights Project.
“The state has been carefully dealing with imams for a long time because it knows the influence they have,” he said. “The detentions and imprisonments of the past few years are just the culmination of three decades of repression designed to constrict Uyghur culture and religion.”
A spokesman for the Chinese government told the BBC that Xinjiang “enjoys unprecedented freedom of religious belief”.
“Xinjiang’s ‘de-radicalisation’ effort has effectively contained the spread of religious extremism and made a great contribution to global ‘de-radicalisation’ efforts,” he said.
The beginnings of ‘re-education’
Targeting of the Turkic ethnic groups in north-western China is not a new phenomenon. Muslim minorities suffered long periods of repression between the 1950s and 1970s, when Qurans were burned, mosques and cemeteries desecrated, and traditional dress and hair styles prohibited.
The 1980s brought a period of relative openness and revival. Damaged mosques were repaired and new mosques built; religious festivals allowed and imams and other figures permitted to travel; and the Quran translated for the first time into Uyghur, by the prominent Uyghur scholar Muhammad Salih Hajim.
But a violent uprising by Uyghur militants in 1990, in the town of Baren in Xinjiang, precipitated a crackdown by the Chinese state and the beginning of a two-decade period of gradually tightening control. Imams, seen by authorities as influential community figures, were increasingly required to demonstrate loyalty to the state.
In the early 2000s, many imams were compelled to attend formalised education courses that foreshadowed the mass “re-education” programmes pursued today against the general population. According to Human Rights Watch, roughly 16,000 imams and other religious figures underwent “political re-education” between 2001 and 2002.
Among them was Tursun, an imam who was first detained in 2001 for translating prayers from Arabic into Uyghur for his congregation, according to his niece.
Tursun’s two-year stint in a “re-education through labour” camp marked the beginning of a two-decade ordeal at the hands of the state, his niece told the BBC from outside China. Her uncle was freed from the labour camp in 2002 but constantly harassed by police, she said, and frequently taken away again for two-week periods of “study”. Then in 2005, he was detained again but this time sentenced to four years in prison.
“We were not given any notice from the court,” his niece said. “My family went to the police station to enquire about his fate and the police gave them a handwritten note containing information about his prison sentence and the address of the prison.”
Tursun was released from prison in 2009, only to be detained again in 2017 after the hardline politician Chen Quanguo was put in charge of Xinjiang and escalated the campaign against the Uyghurs.
As appears to be the case with other imams in the region, Tursun’s family was subsequently targeted en masse, said his niece, who had left China by that time.
“After I heard the news of my uncle and his wife’s arrests, I heard that my mother and many of my relatives were also arrested. Anyone over 14 was taken away,” she said. “For the last four years I have been trying to find information regarding their whereabouts, especially my mother.”
About a month ago, Tursun’s niece learned that her mother had been sentenced to 13 years in prison and her younger brother to five years. She doesn’t know what the charges were. Her father is already serving a life sentence, she said, issued in 2008 for “illegal preaching” and “separatism”.
“My mother was a simple housewife and she was sentenced to 13 years,” she said. “I cannot imagine how long my uncle has been sent to prison for.”
They were targeted “because of their invisible authority”, she added. “The state has tried everything to break them, to destroy them. And not only the religious leaders but also those who practise Islam quietly, and take pride in being Uyghur. They have made every effort to dig them out and destroy them.”
Some that disappear into detention never come out. Eighteen imams named in the database were reported to have died while in custody or shortly after.
Nurgazy Malik, a father of two, graduate of the official Xinjiang Islamic Institute and editor-in-chief of a state-approved religious magazine, reportedly died in detention in November 2018. Unconfirmed reports say Chinese authorities acknowledged his death to his family, but did not produce a body — a situation echoed in other, similar reports. Malik’s friends and relatives held a funeral for him in Kazakhstan all the same.
A secret prayer
In late 2019, as its network of “re-education” camps drew intense international scrutiny, China claimed it had released everyone from the system. Significant numbers had been released, into house arrest or into the otherwise controlled environment of Xinjiang, but rights groups say many were simply transferred to formal prisons.
There is also evidence that many thousands had been in prison all along. Incarceration rates exploded in Xinjiang in 2017 and 2018, according to reporting by the New York Times and others, sweeping up at least 230,000 people — about 200,000 more than in previous years.
According to Chinese government data, criminal arrests in Xinjiang accounted for 21% of the country’s total in 2017, despite the region having about 1.5% of the population.
Unlike the “re-education” system, formal prison sentences should create a paper trail. But the court documents are “nowhere to be found”, according to Gene Bunin, the researcher behind the Xinjiang Victims Database.
According to Bunin, only 7,714 criminal verdicts are available for Xinjiang for 2018, despite the region logging 74,348 criminal cases that year. The near total absence of verdicts on charges typically levied against religious Uyghurs, like “propagating extremism” and “inciting separatism”, suggests China is intentionally scrubbing the record.
Where official documents are available and contain details, offences can be shocking in their innocuity.
In one 2018 verdict, now deleted from the government records but archived by the Xinjiang Victims Database, a 55-year-old Uyghur farmer already serving 10 years for “propagating extremism” had his sentence doubled after he “used a disguised and simplified method to perform the namaz prayer in the prison dormitory”.
Essentially, Ismayil Sidiq secretly prayed in prison. He was reported by a cellmate and charged with “illegal religious activities” and “inciting ethnic hatred and discrimination” — the latter charge for allegedly shouting that Uyghurs should not inform on one another. He will be eligible for release in 2038.
Those who are detained in camps stand a better chance of release after a few months or years, but release in Xinjiang does not necessarily mean freedom.
Memet, a Uyghur who fled Xinjiang, told the BBC his father was detained in 2017 after many years serving peacefully as an imam. Memet had been able to learn news of his family over the years from an acquaintance in Xinjiang — someone distant enough from the family that she felt safe messaging abroad from her WeChat account — but Memet heard virtually no news of his father’s condition for four years.
Then recently he heard his father had been released, and Memet imagined speaking to him for the first time in years. He asked the family acquaintance if she would be willing to find his father and connect them again via her phone.
On the appointed day, Memet received a message on his WeChat account from the acquaintance. She said she had found his father, but he had told her it would be better if he didn’t speak to his son. And after she sent the message, she blocked Memet from contacting her again.
By James Clayton
North America technology reporter
Apple has taken down one of the world’s most popular Quran apps in China, following a request from officials.
Quran Majeed is available across the world on the App Store – and has nearly 150,000 reviews. It is used by millions of Muslims.
The BBC understands that the app was removed for hosting illegal religious texts.
The Chinese government has not responded to the BBC’s request for comment.
The deletion of the app was first noticed by Apple Censorship – a website that monitors apps on Apple’s App Store globally.
In a statement from the app’s maker, PDMS, the company said: “According to Apple, our app Quran Majeed has been removed from the China App store because it includes content that requires additional documentation from Chinese authorities”.
“We are trying to get in touch with the Cyberspace Administration of China and relevant Chinese authorities to get this issue resolved”.
The company said it had close to one million users in China.
The Chinese Communist Party officially recognises Islam as a religion in the country.
However, China has been accused of human rights violations, and even genocide, against the mostly Muslim Uyghur ethnic group in Xinjiang.
However, it is not clear what rules the app has broken in China. Quran Majeed says it is “trusted by over 35 million Muslims globally”.
Last month, both Apple and Google removed a tactical voting app devised by jailed Russian opposition leader Alexei Navalny.
Russian authorities had threatened to fine the two companies if they refused to drop the app, which told users who could unseat ruling party candidates.
China is one of Apple’s biggest markets, and the company’s supply chain is heavily reliant on Chinese manufacturing.
Apple chief executive Tim Cook has been accused of hypocrisy from politicians in the US for speaking out about American politics, but staying quiet about China.
Mr Cook criticised Donald Trump’s ban of seven Muslim-majority countries in 2017.
However, he is also accused of complying with the Chinese government over censorship – and not publicly criticising it for its treatment of Muslim minorities.
The New York Times reported earlier this year that Apple takes down apps in China if deemed off limits by the Chinese government. Topics that apps cannot discuss include Tiananmen Square, the Chinese spiritual movement Falun Gong, the Dalai Lama, and independence for Tibet and Taiwan.
Benjamin Ismail, project director at Apple Censorship, said: “Currently Apple is being turned into the censorship bureau of Beijing.
“They need to do the right thing, and then face whatever the reaction is of the Chinese government.”
Another popular religious app, Olive Tree’s Bible app, was also taken down this week in China. The company told the BBC they had removed the app themselves.
“Olive Tree Bible Software was informed during the App Store review process that we are required to provide a permit demonstrating our authorization to distribute an app with book or magazine content in mainland China,” said a spokesperson.
“Since we did not have the permit and needed to get our app update approved and out to customers, we removed our Bible app from China’s App Store.”
On Friday, The Mac Observer reported that Audible, the Amazon owned audiobook and podcast service, removed its app from the Apple store in mainland China last month “due to permit requirements.”
On Thursday, Microsoft said it was shutting down its social network, LinkedIn, in China, saying having to comply with the Chinese state had become increasingly challenging.
The decision was made after the career-networking site faced questions for blocking the profiles of some journalists.