Engaged in a border war with Japan in the Far East and fearing the German advance in the west, the Soviet Government began secret negotiations with Germany, in 1939, for a non-aggression pact. They still continued to talks with the Allies against Germany. Finally, they announced that they would side with Hitler.

The Pact provided an increase in German and Soviet trade and Soviet economic aid in Germany. It was also a pact of friendship and non aggression. The clause included a special secret section stating that Germany and the Soviet Union would split up Poland once it was conquered.

On September 1, 1939, Germany invaded Poland from the west, 16 days later the Soviets invaded Poland from the east. They easily conquered Poland and began talks on how they would divide it up. September 29, Germany and the Soviets signed another treaty. This treaty acknowledged the supremacy of the two powers and their interests in Poland. Although, they signed two treaties and shared a country, Germany and the Soviet Union were not really friends. Germany proved this on June 22, 1941, when they invaded the Union of Soviet Socialist Republics. After this event, Italy, Germany, and Japan were the axis powers. And, the US, Great Britain, and the USSR fell into place as the Allied Forces.