Germany then revived its Anti-Comintern Pact , enlisting many European and Asian countries in opposition to the Soviet Union . The Soviet Union and Japan remained neutral towards each other for most of the war by the Soviet-Japanese Neutrality Pact . The Soviet Union ended the Soviet-Japanese Neutrality Pact by invading Manchukuo on 9 August 1945 , due to agreements reached at the Yalta Conference with Roosevelt and Churchill
Yalta Conference
Yalta Conference
Axis powers