The USSR's nuclear program receives plans for the United States plutonium bomb from Klaus Fuchs at the Los Alamos National Laboratory.

Soviet Union

Country in Eurasia (1922–1991)

The Union of Soviet Socialist Republics (USSR), commonly known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 until it dissolved in 1991. During its existence, it was the largest country by area, extending across eleven time zones and…

Nuclear weapon

A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission or a combination of fission and nuclear fusion reactions, producing a nuclear explosion. Both bomb types release large quantities of energy from relatively…

Klaus Fuchs

German-born British physicist and atomic spy (1911–1988)

Klaus Emil Julius Fuchs was a theoretical physicist, atomic spy, and communist who supplied information from the American, British, and Canadian Manhattan Project to the Soviet Union during and shortly after World War II. While at the Los Alamos Laboratory, Fuchs was responsible…

Los Alamos National Laboratory

Laboratory near Santa Fe, New Mexico

Los Alamos National Laboratory is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, in the American southwest. Best known for its central role in helping develop…