Who was the leader of the Soviet Union during World War II?

The leader of the Soviet Union during World War II was Joseph Stalin. He was in power from the mid-1920s until his death in 1953 and played a crucial role in the war effort against Nazi Germany. Under his leadership, the Soviet Union underwent significant industrialization and militarization, which allowed it to emerge as one of the key Allied powers during the conflict. Stalin's leadership was marked by both authoritarianism and significant military strategy, especially during pivotal moments such as the Battle of Stalingrad and the overall Eastern Front campaign. His policies and decisions had a profound impact on both the Soviet Union's wartime performance and the post-war landscape of Europe.