In the early twentieth century, America experienced big, but different type of wars: Second World War and the Vietnam War. Although in both wars America tried to use its super power to achieve the worldsf peace, its specific policies and what they got as a result were totally different. One of them got worldfs brilliant reputation, but the other became one of the most hated memories among American. Strategically, however, the U.S. foreign policy after WWI did not basically change: they took neutral position, always only at the beginning.
             WWII started in 1939 as Germany invaded Poland because of their frustration and humiliation by the Treaty of Versailles, which was also called slave-treaty. Soon, this war expanded through whole Europe, but the U.S. involvement didnft occur immediately following the beginning of the war. If the U.S. intervened the war, it broke the Neutrality Act of 1935, which prohibits the U.S. from giving assistance to any nation that is involved in foreign conflicts. Also, the policy called Lend-Lease Act guaranteed that the U.S. stayed out of war. At the beginning of the war, Franklin D. Roosevelt followed that policy, and American national security was not in jeopardy at that moment. On December 7th in 1941, the situation dramatically changed. Japanese army surprisingly attacked the American navy at Pearl Harbor and declared war to the U.S. Considering about this serious situation and the effect of the Great Depression, the U.S. started to involve the war by breaking their neutral position. In addition, in Truman Doctrine, he expressed his fear of a revived isolationism and the communist expansion to European countries. Trumanfs plan to assist European countries at the request of the government followed the American foreign policy of humanitarianism as the government would not allow a country to be overtaken by another country without U.S. intervention. As the war came close to the end, the go...