Which country was an allied power in World War II?

The Soviet Union was an Allied power in World War II because it entered the war on the side of the Allies after being invaded by Germany in 1941. Following Hitler's betrayal of their non-aggression pact, the Soviet Union became a significant force against the Axis powers, engaging in various battles and ultimately playing a crucial role in the Allied victory. With their military strength, sacrifices, and contributions to the war efforts, the Soviet Union helped turn the tide of the war and played a pivotal role in the defeat of Nazi Germany.