Atomic espionage for the USSR

Klaus Fuchs

Fuchs, a German communist, fled to Britain in 1933. He took a doctorate in physics at Edinburgh; in 1939 he was interned on the Isle of Man, then in Canada, and in 1941 he returned to Edinburgh and joined the British atomic programme, Tube Alloys.^2,4

In late 1941 he offered information to the Soviets through the exiled German communist Jürgen Kuczynski and was put in touch with the GRU. His codename was REST; in 1942 he was handed over to Ursula Beurton (SONYA), whom he met regularly in Banbury.²

In 1943 he joined the Manhattan Project with a British team. According to the US Department of Energy, at Los Alamos he worked in the Theoretical Division and passed on detailed information on atomic weapons design.^1,2

Gold, Greenglass, Hall

Fuchs's contact was an American, Harry Gold, who according to MI5 had been working for the Soviets since 1934; they met in places including New York and Santa Fe.²

David Greenglass, a US Army machinist, worked on implosion at Los Alamos. He passed information through his wife Ruth to Julius Rosenberg – an engineer who, according to the Department of Energy, led an industrial espionage ring but never himself worked on the Manhattan Project.¹

Theodore Hall, a long-time communist, made contact with Soviet intelligence at Los Alamos in November 1944. His information on implosion served as an important supplement to, and confirmation of, Fuchs's material.¹

How Fuchs was caught

Messages read in the Venona programme revealed Fuchs's meetings with Gold; in the summer of 1949 he was identified under the codenames CHARLES and REST. From July 1949 MI5 monitored his mail and telephone calls but found nothing incriminating.^2,5

The interrogations were conducted by Jim Skardon: he confronted Fuchs in December 1949, and about a month later Fuchs confessed. His confession was lengthy but partial. He was arrested on 2 February 1950, pleaded guilty to breaching the Official Secrets Act and received the maximum sentence of fourteen years' imprisonment.^1,2,3

After his release he went to East Germany, where he died in 1988.²

A chain of confessions in the United States

On 22 May 1950 Harry Gold confessed to the FBI. His arrest led to Greenglass, who was charged on 16 June 1950.^1,3

On 17 July 1950 Julius Rosenberg was arrested in New York, and on 11 August Ethel Rosenberg. Morton Sobell, who had left for Mexico with his family on 22 June, was deported and detained by the FBI on 18 August 1950 at the International Bridge in Laredo.³

Trial and sentence

The trial before the federal court in New York began on 6 March 1951. On 29 March the jury found the Rosenbergs and Sobell guilty, and on 5 April the Rosenbergs were sentenced to death and Sobell to 30 years in prison. Greenglass had pleaded guilty and received 15 years; he was released on 16 November 1960. Ruth Greenglass was never charged.^1,3

On 19 June 1953 the US Supreme Court vacated the stay of execution granted by Justice Douglas on 17 June. The Court held that the Atomic Energy Act of 1946 did not repeal or limit the penalty provisions of the Espionage Act of 1917; Justices Black, Frankfurter and Douglas dissented.⁶

President Eisenhower twice refused clemency (11 February and 19 June 1953). The Rosenbergs were executed on the evening of 19 June 1953 at Sing Sing prison. Both maintained their innocence to the end.^1,3

Hall without a trial, and the consequences

The FBI learned about Hall in the early 1950s, but Hall admitted nothing and the matter was quietly dropped; the Venona evidence was too sensitive to use in court.^1,7

On 29 August 1949 the USSR carried out its first nuclear test; according to the Department of Energy the device was virtually identical in design to the one tested at Trinity four years earlier. The Department estimates that espionage sped up the Soviet programme by at least 12 to 18 months, and that most of the spies acted for ideological reasons rather than money.¹