World War II officially ended in 1945, marked by the unconditional surrender of Nazi Germany on May 7, followed by the dropping of atomic bombs on Hiroshima and Nagasaki in August. These actions led to Japan's surrender on September 2, 1945, which effectively concluded the war. The end of the conflict resulted in significant geopolitical changes, including the emergence of the United States and the Soviet Union as superpowers, the establishment of the United Nations, and a shift towards decolonization in various parts of the world over the subsequent years.