After the war, he returned to England to head the Theoretical Physics Division at the newly formed British Atomic Energy Establishment.
Decoded messages led to having Fuchs placed under surveillance in 1949. When questioned, Fuchs confessed to passing atomic secrets to the Soviets. Fuchs was tried and convicted in Britain. Fuchs served 10 years of a 14 year sentence. He then emigrated to East Germany. He died in East Berlin in 1988.
The Soviet atomic bomb project was greatly aided by the information given to them by Fuchs and later the Rosenbergs.
