Near the end of World War II, the principal Allied war powers made plans for exploitation of German science. In light of the implications of nuclear weapons, German nuclear fission and related technologies were singled out for special attention. In addition to exploitations, denial was an element of their efforts, i.e., the Americans and Russians conducted their respective operations to try to deny German technology, personnel, and material to the other party.
Application of denial often meant getting there first, which to some extent put the Russians at a disadvantage in some geographic locations, even if the area was to be in the Russian zone of occupation. When it came to applications of exploitation and denial, all parties were sometimes heavy-handed.[64][65][66][67][68]
A general US denial and exploitation effort was Operation Paperclip. Operations directed specifically towards German nuclear fission were Operation Alsos and Operation Epsilon, the latter being done in collaboration with the British. In lieu of the codename for the Russian operation, if it had one, it has been referred to by Oleynikov as the Russian "Alsos".[69]