History of Vietnam since 1945 unstable as no government could keep power for long. There were more coups, often more than one every year. The Communist-run Viet Cong expanded their operation and scored some significant military victories during this period. In 1965, US President Lyndon Johnson sent troops to South Vietnam to secure the country and started to bomb North Vietnam, assuming that if South Vietnam fell to the Communists, other countries in the Southeast Asia would follow, in accordance with the domino theory. Other US allies, such as Australia, New Zealand, South Korea, Thailand, the Philippines, and Taiwan also sent troops to South Vietnam.
Vietnam Syndrome brought about because of the Vietnam War and with feelings of doubt over the morality of America's intentions and actions during the war. Reagan, however, argued that America had fought for "a noble cause" and blamed the war in Vietnam exclusively on North Vietnam's aggression: Vietnam Syndrome Vietnam Syndrome, in U.S. politics, is a term used to refer to public aversion to American overseas military involvements, following the domestic controversy over the Vietnam War, which ended in 1975. Since the early 1980s, the combination of a public opinion apparently biased against war, a relative reluctance to deploy ground troops and