Between the Wars: 1919-1941 United States involvement in World War II was inevitable. Circumstances preceding the entrance of the United States into this foreign conflict proved that she would not be able to avoid active participation. With a government increasingly changing its views from isolationism to internationalism, and with each successive presidency's administration doing the same, the United States would not be able to hold out from World War II as long as the conflict was waged. It even became obvious, when President Roosevelt reacted to the German blitzkrieg in France by declaring an unlimited national emergency in the United States, that involvement in World War II had become unavoidable. The dominance of isolationist sentiment in the foreign policy of the United States was increasingly reversed to the dominance of internationalist sentiment. In 1919, the United States Congress voted against signing the Treaty of Versailles.
This treaty called for joining the League of Nations, a serious isolationist adversary. However, in 1921, President Warren G. Harding, a man who, himself, condemned the United States joining the League of Nations, held the Washington Naval Conference. In this meeting of Asian and European countries, the United States actively participated in three treaties to begin to ease the tension already forming in the Pacific. In 1932, when the League of Nations proposed an economic boycott against Japan for reparation of the occupancy of Manchuria, President Hoover refused to participate, in fear of involvement in an Asian war. Just eight years later, during the Roosevelt administration, the United States placed an embargo on exports of scrap metal, oil, and aviation fuel to Japan because of its intolerance for Japanese military presence in European colonies in Asia.
Japans dependency on these materials from the United States would be crippling. When German turned the forces of its blitzkrieg on France, and France subsequently surrendered, President Franklin Delano Roosevelt declared an unlimited national emergency for the United States. The European conflict created the need for an absolute effort to strengthen national defense. Such a declaration of internationalism held the United States at the point of no return. Further involvement in World War II became unavoidable. The Lend-Lease Act, an agreement that provided Britain with American war ships, began active involvement of the United States in World War II.
The meeting between American and British military leaders to plan a joint strategy, as well as the Atlantic Charter, a joint statement from president Franklin Roosevelt and British Prime Minister Winston Churchill proclaiming the Allied defensive intents, the United States continued its entanglement in World War II. Due to the changes that were beginning to carry United States foreign policy from that of isolationism to internationalism, as well as the events that began to unfold because of this, involvement in World War II was unavoidable. Because of the position of the United States as a major world power, involvement in a world war was unavoidable. It was with the events that took place and the actions that were taken, however, that this involvement was hastened. It was not by much, however, that this entrance into World War II was accelerated. The United States would have been lead into the conflict when the impending attack of an aggressive power had struck..