Josef Stalin was the leader of?

Josef Stalin was the leader of the Soviet Union from the mid-1920s until his death in 1953. He played a crucial role in transforming the USSR into a major world power through industrialization and collectivization, although his policies also led to widespread famine and political repression. Stalin's regime was characterized by totalitarian rule, marked by purges, mass executions, and the establishment of a strong state security apparatus. His leadership significantly shaped the course of 20th-century history, particularly during World War II and the early Cold War.