a) Harry S. Truman

President Harry S. Truman made the momentous decision to use atomic bombs during World War II. Faced with the prospect of a prolonged and costly invasion of Japan, Truman authorized the use of atomic weapons in the hope of bringing a swift end to the war. The bombings of Hiroshima and Nagasaki in August 1945 led to Japan’s surrender but also opened a new and controversial chapter in warfare and international politics.