NOVA Online | Secrets, Lies, and Atomic Spies ·

08 Aug 2024, 00:00

Read Venona Intercepts
The February 9, 1944 cable:
Klaus Fuchs and Harry Gold
Back to Intro This cable concerns a meeting that took place between Klaus Fuchs (cover name "Rest"), a young British physicist who worked on the Manhattan Project and may have given away the most valuable atomic secrets of all, and Harry Gold ("Goose"), who ferried those secrets to the Soviets.

Emil Julius Klaus Fuchs was born in Germany in 1911. Hounded by the Nazis because of his Communist proclivities, Fuchs fled to England, where he became a naturalized citizen. A bright young physicist, he was hired to work on the British atomic bomb project in 1941. Soon afterward he started spying for the Soviets.

Released from prison the day before, Klaus Fuchs, 48, prepares to board a flight to East Germany on June 24, 1959.

When the United States entered the war, Great Britain merged its atom-bomb effort with America's, sending over 15 of its leading scientists. Arriving in the States in late 1943, Fuchs began working with a Manhattan Project team based at Columbia University. The group was investigating ways to separate U-235 from U-238. (U-235 is better suited to generating an atomic explosion than the heavier isotope of uranium.)

As this cable suggests, Fuchs kept right on spying once he reached America, offering secrets about the two processes for separating isotopes of uranium then being explored by Manhattan Project scientists—gaseous diffusion and the electromagnetic method. The cable was sent by New York-based KGB officer Leonid Kvasnikov ("Anton") to Lt. Gen. Pavel Mikhailovich Fitin ("Viktor"), who headed the foreign intelligence section of the KGB from 1940 to 1946. In August 1944, Fuchs was transferred to the theoretical division at Los Alamos, home of the Manhattan Project. When the war ended, Britain reestablished its own atomic-bomb project, which Fuchs rejoined in mid-1946.

Harry Gold spent 16 years behind bars for his role as courier for Fuchs and other spies.

Three years later, in 1949, the FBI turned over to British counterintelligence Venona decryptions like this one as well as other evidence that Fuchs was a Soviet agent. MI5 officers began questioning Fuchs in December of that year, and on January 24, 1950, Fuchs confessed. Convicted at trial of espionage, he was sentenced to 14 years in prison. When he was released in 1959 after serving nine years, he moved to Communist East Germany, where he became a lecturer and director of a nuclear research institute. Fuchs died in 1988.

Fuchs' confession and decrypted Venona cables led the FBI to Harry Gold. They searched his house, uncovering significant evidence of long-term industrial and atomic espionage for the Soviet Union. Like Fuchs, Gold broke under the pressure of questioning and confessed everything. He was given a 30-year sentence and served 16 before being paroled in 1966. Gold died in 1974.

The February 9, 1944 cable
Note: Consult the footnotes at the end of the cable for identities of individuals and definitions of terms appearing in capital letters.

Fuchs & Gold intercept page 2

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NOVA Online | Secrets, Lies, and Atomic Spies

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