German-Soviet Nonaggression Pact, also called Nazi-Soviet Nonaggression Pact, German-Soviet Treaty of Nonaggression, Hitler-Stalin Pact, Molotov-Ribbentrop Pact, (August 23, 1939), nonaggression pact between Germany and the Soviet Union that was concluded only a few days before the beginning of World War II and which divided eastern Europe into German and Soviet spheres of influence.