Espionage, Soviet Spies History 31 Communism 7 Cold War 5 Communists 4 Subversive activities 4 more ... Art historians 3 Chemists 3 Cryptography 3 Gay men 3 Prisoners 3 Relations 3 Secret service 3 World War, 1939-1945 3 Atomic bomb 2 Espionage 2 Intelligence officers 2 Librarians 2 Officials and employees 2 Politics and government 2 Technology transfer 2 Anti-communist movements 1 Art and society 1 Artists 1 Assassination 1 Authors, American 1 Biography 1 Defectors 1 Electric engineers 1 less ...