Soviet-Japanese Neutrality Pact Is Signed
The Soviet–Japanese Neutrality Pact was signed between Russia and Japan two years after the war between Russia and Japan at the Manchurian and Mongolian borders slowed inconclusively.
The treaty called for the two nations to observe neutrality when any one of the two signing nations was invaded by a third nation. Both nations also pledged to respect the sovereignty of Japan's puppet state of Manchukuo and Russia's puppet state the Mongolian People's Republic.
The Soviet-Japanese Neutrality Pact was signed in April 1941. Cross-border skirmishes in Japanese-occupied Manchuria and in Mongolia motivated Japan to sign in order to keep Russia from tying it down in northern Asia while it accomplished its goals of territorial expansion in Southeast Asia. Russia signed it because it was focusing its military might to the west, supplying Germany with food and war material, in line with the August 1939 Molotov-Ribbentrop Pact, but also preparing for a confrontation with Germany itself. That came in June 1941, when Germany suddenly invaded the Soviet Union.