America's extensive involvement in Vietnam begun under the presidency of Harry Truman, who provided France with support to maintain rule in the region.

President Truman first became involved in Vietnam in July 1950, when he sent France $15 million in military aid to help them fight against the Vietminh.

Under the Truman Doctrine, President Truman committed to assist any country under threat of a communist takeover. At the time the USA was fighting a war in Korea through the proxy of a UN task force. Truman became concerned the French would be defeated by the communist Vietminh and communism would then spread throughout Asia.

President Truman's role in Vietnam was significant due to the obligation it created to the region. Once he committed support to Vietnam this continued under each consecutive president. While each had doubts about further committing the USA, neither did they want to be the president who lost Vietnam to communism.