The realist school of thought advocates anarchy and fights for its own selfish reasons to preserve the nation's interest. On December 7, 1941, after the Japanese Air Force attack on Pearl Harbor in Hawaii, the U.S. Army was caught by surprise, turning the entire nation's attention against Japan. President Harry S. Truman made the decision in 1945 to attack Japan with nuclear bombs first on Hiroshima and then three days later on Nagasaki. A few days later, Japan surrendered and World War II came to an end. Realist scholars argue that the decision made was unnecessary. The deaths between the two cities were around 200,000, in Hiroshima there were 90,000 deaths and Nagasaki 37,000 deaths, not counting the deaths of the wounded and after nuclear contamination. Although people usually think that realism is related to power, strength and attack, they knew that then Japan was defeated before the bombs were dropped. Truman's chief of staff, Admiral William Leahy, said in his memoirs that “the use of this barbaric weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender." One of the main reasons behind the attack was to demonstrate to the Soviet Union that we had nuclear weapons and were not afraid to use them against our enemies. The main excuse used was that the destruction of the two cities minimized the US military losses that would be caused by the war battles. At that time General Eisenhower expressed his frightening opinion on the devastating decision, Secretary of War Henry L. Stimson thought the strategic move was necessary to win against Japan. Eisenhower thought the opposite, he also tried... with paper... other powers did it too. The Non-Proliferation Treaty was created to reduce the nuclear weapons of the five original states (the United States, Russia, China, France and the United Kingdom) and prevent other states from acquiring them. Realists believe that there is no higher power that should control or regulate a state, ironically the United States promoted weapons development and is now focused on preventing it. The attack on Japan opens a Pandora's box and a prospect of fear for the future. The NPT goes against rational actors, if one state goes for nuclear energy why shouldn't others have the same level of defense mechanism? At least the NPT allows nuclear energy enrichment. Japan is… Many realists say that alliances are not normal and once the purpose is achieved, above all, the union disappears. The new nuclear age creates additional concerns due to non-state actors..