日ソ中立条約
Later in 1941, Japan, as a signatory of the Tripartite Pact, considered denouncing the Soviet–Japanese Neutrality Pact, especially after the German invasion of the Soviet Union, but it made the crucial decision to keep the pact and to expand southwards by instead invading the European colonies in Southeast Asia. That had a direct bearing on the Battle of Moscow since the absence of a Japanese threat allowed the Soviets to move large forces from Siberia and to send them to the front against the Germans.