Klaus Fuchs, a brilliant German nuclear physicist, was sentenced to 14 years in prison by a British court on March 1, 1950. He had confessed to British security service MI5 that he had given the Soviets everything he knew about British and American nuclear weapons projects for seven years. Frank Close, emeritus professor of physics in Oxford, tells the story in his latest book. It has been previously reported, but Close adds previously unavailable details from British, American, and Russian intelligence archives.
As a young man in Germany, Fuchs had fought with the Communists against the National Socialist threat. He fled to Great Britain in 1933, where he continued his studies. When the war broke out, he was interned as an enemy alien and shipped to Canada.
By 1939, the world's physicists knew that the atom could be split and theoretically used to build a bomb with unprecedented power. In March 1940, two other German refugee researchers, Rudolf Peierls and Otto Frisch, proposed to the British government how this could be done. Fearing that the Germans will get a bomb first, the British have set up a program. Fuchs was brought back from Canada to participate. By then the Russians had started their own theoretical work on a bomb.
When the British realized that their resources were insufficient, they agreed to merge their program with the "Manhattan Project" of the Americans. Fuchs, Peierls and others were seconded to this. The Americans successfully tested a nuclear device in July 1945 – the "Trinity" test. Weeks later, they bombed Hiroshima. They then stopped working with the British. Still determined to have a bomb, the British restarted their program. Fuchs was brought back in.
Narrow thinks MI5 should have caught Fuchs earlier. But MI5 believed that her information was insufficient to warrant a ban on him and her desire to save Britain from the excesses of McCarthyism, which was overtaking America. The Americans were contemptible of British failure. However, they took similar risks. Robert Oppenheimer, a brilliant scientist with many connections to the left, managed his weapons program. This game paid off. In the case of Fuchs, there was a dropout: Nevertheless, he was only caught because the code breakers finally succeeded in deciphering the messages of his Soviet dealers from the war in the late 1940s.
The Russians detonated their own nuclear device in August 1949, just four years after Trinity. The Americans could not believe that the Russians with their backward industry and technology without Fox’s help would have been so successful. They were not the only ones who underestimated the innate scientific and technical skills of the Russians and Stalin's ruthless determination. Hiroshima convinced him that he was risking nuclear blackmail from the Americans. He hired thousands of slave laborers and the best scientists and engineers in the country. They soon gave him what he wanted.
In the 1990s, some former Soviet intelligence officers claimed that it was their information that gave Russian success. The scientists angrily published the secret protocol that demonstrated their accomplishments. They freely admitted that the secret services had enabled them to avoid false traces. However, they pointed out that the secret services left many questions unanswered that they had to solve themselves.
How much difference did Fuchs make? Close, like many others, blames the CIA for not predicting the Soviet bomb. However, as early as 1946, the CIA estimated that they could possibly produce a bomb sometime between 1950 and 1953. A current estimate says that Fuchs allowed the Russians to get their bomb six months to two years faster. This seems to be irrelevant to the decades of nuclear confrontation between the United States and Russia.
Fuchs never explained his motives. They seem to have been a mixture: loyalty to an ideal of communism and the belief that nobody should claim a monopoly on the secrets of nature. His friends and colleagues felt his personal betrayal deeply. Some believed, however, that he was an honorable man in his own way. Over time, his betrayal seems to some – including Frank Close – less undeniably hideous than it was then.
Trinity: betrayal and hunt for the most dangerous spy in history
Allen Lane 528pp £ 25
Rodric Braithwaite was British Ambassador to the Soviet Union (1988-91) and is the author of Armageddon and paranoia: the nuclear confrontation (Profile, 2017).