'Coffee' was the designation of a British and Soviet party trained in the UK by the Special Operations Executive for the NKVD as part of a joint agreement between the SOE and the NKVD on co-operation between the two entities (summer 1943).

Some co-operation did occur, notably in the form of SOE assistance to the dropping of Soviet agents into occupied Europe, but finally the 'mission achieved precious little…The Soviet authorities had no desire to co-operate closely with the British, and the British were equally unenthusiastic…'

More specifically, 'Coffee' was the codename for a group of four agents sent to the UK by the NKVD (People’s Commissariat for Internal Affairs, or Soviet internal security service) to be trained by the SOE in order that they could be parachuted into Nazi-occupied Austria. The mission did not take place, and the four men were returned to the USSR and almost certainly executed in October 1943.