nov 1, 1955 - Start of the Vietnam War
Part of an overall operation by Truman's America to contain the geographical spread of communism thus demonstrating that fear of communism was the main motive of foreign policy under Truman. By 1964 there were already 23,000 U.S troops involved. The Vietnam War was much larger than any other task to contain communism.
Added to timeline:
20th century US foreign policy