Mezue nkebi ahịrịokwu a: N'afọ 1939, mgbe mgbalị ndị e mere iji soro Britain na France jikọọ aka n'agha megide Germany kụrụ afọ n'ala, Soviet Union gbanwere n'ụzọ dị ịrịba ama n'ebe Nazi Germany nọ. Ihe fọrọ nke nta ka ọ bụrụ otu afọ ka Britain na France bịanyesịrị aka na nkwekọrịta Munich na Germany, Soviet Union bịanyekwara aka na nkwekọrịta Germany, ma nke agha ma nke akụ̀ na ụba n'oge mkparịta ụka sara mbara. Mba abụọ ahụ mechiri Molotov-Ribbentrop Pact na German-Soviet Commercial Agreement n'August 1939. Nke mbụ ahụ mere ka Soviet nwee ike ịchị Lithuania, Latvia, Estonia, Bessarabia, ebe ugwu Bukovina, na ọwụwa anyanwụ Poland, ebe ndị Soviet nọgidere na-anọpụ iche n'ụzọ iwu. Na ngwụcha ọnwa Nọvemba, n'enweghị ike ịmanye Republic nke Finland site n'ụzọ ndọrọ ndọrọ ọchịchị ịkwaga ókèala ya site na Leningrad, Stalin nyere iwu ka ndị agha nke Soviet Union na-aga n'ihu n'ihu.
mwakpo a wakporo Finland. N'ebe ọwụwa anyanwụ, ndị agha Soviet meriri ọtụtụ ndị agha n'agha ndị ha na Alaeze Ukwu Japan lụrụ n'afọ 1938 na 1939. Otú ọ dị, n'April 1941, USSR bịanyere aka na Soviet-Japanese Neutrality Pact na Japan, na-amata ịdị n'otu ókèala Manchukuo, bụ́ steeti ndị Japan na-achị.