This study will argue that, in terms of shaping United States foreign policy in the twentieth century, World War II was more influential than World War I, the Cold War, or the Vietnam War. The involvement of the United States in World War I was certainly a significant event in the history of the United States, but World War I simply did not have the lasting effect which World War II had in terms of uniting the destinies of the United States and Europe. The United States essentially adopted an isolationist attitude after World War I, and this isolationism intensified during the 1930s and the Depression years.
On the other hand, the Cold War and the Vietnam War were among the direct and indirect results of World War II. Both the Cold War and the Vietnam War would not have even come into existence had not World War II taken place and created the distrust and enmity which emerged between the United States and the Soviet Union after World War II.
Stephen Ambrose, in Rise to Globalism, shows how the decision which led to the entrance of the United States into World War II was made and how it resulted in victory over tyrants and established the nation as one of the two superpowers in the world, along with the Soviet Union. Unfortunately, or perhaps inevitably, the two superpowers emerged from World War II as bitter foes in a Cold War which would last for more than four decades before the collapse of the Soviet Union brought it to an end.
The involvement of the United States in World War II was crucial not only because the U.S. played a central role in defeating fascism globally, but because it established the United States as a global force which would confront the Soviet Union in the struggle for the minds, hearts, bodies and nations of the world, especially of the Third World.
From the perspective of the United States, its entrance into World War II prevented a totalitarian takeover by Hitler, Mussolini, et al., and it a...