After World War II, the Allied powers occupied and attempted to rebuild Germany and Japan. Germany was divided between the Western Allies and Soviet Union, with the West focused on treating Germans harshly to prevent a return to militarism. The Nuremberg trials prosecuted Nazi leaders. In Japan, the U.S. dropped atomic bombs on Hiroshima and Nagasaki, leading Japan to surrender and demilitarize under a new democratic constitution, while also prosecuting Japanese war criminals. The United Nations was established with the major Allied powers as permanent Security Council members.