How did germany attacking the soviet union help the allies?

Operation Barbarossa. On June 22, 1941, Adolf Hitler launched his armies eastward in a massive invasion of the Soviet Union: three great army groups with over three million German soldiers, 150 divisions, and three thousand tanks smashed across the frontier into Soviet territory.

Explanation:

The war was fought between Nazi Germany, its allies and Finland, against the Soviet Union and its allies. The conflict began on 22 June 1941 with the Operation Barbarossa offensive, when Axis forces crossed the borders described in the German–Soviet Nonaggression Pact, thereby invading the Soviet Union.