Who was the leader of Russia, the United States, Italy, and Japan during World War II.
Joseph Stalin was the leader of the Soviet Union (not Russia it wasn't called that then) in WW II. The President of the United States was Franklin Delano Roosevelt. The leader of Japan in WW II was Hideki Tojo. The leader of Italy in WW II was Benito Mussolini. However multiple presidents participated in WW II.