The end of World War II brought many changes to the United States. Some were domestic, like the end of the economic depression through the construction of factories for war supplies and by extension the creation of more jobs. Some of the biggest changes that had long-lasting effects, however, were at the international level. At the end of the war the United States was seen as the one of the biggest and most powerful world forces, rivaled only by the Soviet Union, and due to the United States’ involvement in the war, American leaders changed United States foreign policy from isolationism to one based on intervention. This complete change in foreign policy, along with the involvement in the cold war and allies established after World War II, marked the beginning of the United States’ involvement in Vietnam. The American public’s support of the war decreased rapidly as the war progressed and the reasoning for being involved in the war had become lost on both the American society and the American soldiers fighting in Vietnam.
Before its involvement in World War II, the United States had maintained a foreign policy based on isolationism. Isolationism was the idea the United States should have little to no involvement within the conflicts and affairs of foreign countries and after World War I, it was a sentiment that was spread throughout the American public. After the Second World War however, the United States developed a radically different foreign policy. This was due to two reasons; the first being that the United States had emerged out of the war as one of the biggest global powers and the second was that the Soviet Union, a communist nation, was only other country that was as much of a world power as the United States.
In a plea to Congress on March 2, 1947 for financial aid to Greece and Turkey, President Harry S. Truman proclaimed that it should be United States policy to “support free peoples who are resisting attempted subjugation by armed minorities or by outside pressure.” (Schaller, Schulzinger, Anderson; p. 45) In other words, the Truman doctrine, as it became known, set United States foreign policy to one based on intervention and containment. Under this policy, the United States could go to any country that was being “attacked” by communist parties and support the opposing faction through aid. Stemming from the Truman doctrine was the idea that the Soviet Union would support and encourage any communist nation and gather allies to create a kind of global empire. Another move made by the United States that further established this idea of intervention and that again developed from the idea that the Soviet Union was “bent on world conquest” was the Marshall plan (Schaller, Schulzinger, Anderson; p. 61). This plan, created by George C. Marshall in 1947 shortly after Truman spoke to Congress, proposed an aid of $27 billion to repair Europe’s destroyed economy. This plan was to secure United States’ allies in Europe, since allies without any kind of economic power were without use to America, and to ensure that the Soviet Union did not take advantage of Europe’s decimated economy to improve its own global power. These two pieces within American foreign policy, the Truman doctrine and the Marshall plan, helped set the stage for America’s future involvement with Vietnam. After the Second World War, the United States entered a cold war with the Soviet Union. Both countries feared that the other would become the biggest global power and therefore engaged in several threats that included nuclear warfare and strategic moves to gain the upper hand. The United States was most concerned, as aforementioned, with the spread of communism and the thought that it meant more power for the Soviet Union. The domino theory or the thought that if one country