World War II officially ended on September 2, 1945, with the formal surrender of Japan. This act came after the dropping of atomic bombs on Hiroshima and Nagasaki in August of the same year, which prompted Japan's decision to capitulate. The end of the war brought about significant geopolitical changes, leading to the emergence of the United States and the Soviet Union as superpowers and the beginning of the Cold War. Additionally, it resulted in the establishment of the United Nations, aimed at promoting peace and preventing future global conflicts, and addressed many unresolved issues stemming from the war.