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

Joseph Stalin was the leader of the Soviet Union during World War II, which spanned from 1939 to 1945. His leadership was pivotal in the USSR's involvement in the war, particularly after the Nazi invasion in 1941. Stalin played a crucial role in organizing the Soviet military efforts, mobilizing resources, and implementing strategies that eventually led to significant victories, such as the Battle of Stalingrad. His policies and decisions shaped the course of the war on the Eastern Front and contributed to the eventual defeat of Nazi Germany. Understanding Stalin's leadership during this period is vital to comprehending the historical and geopolitical dynamics of World War II and the subsequent Cold War era.