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.
Military history of Australia during the Vietnam War the Many Flags program, hoping to counter the communist propaganda that South Vietnam was merely a US puppet state and to involve as many nations as possible. Thus Australia, as an ally of the United States with obligations under the Southeast Asia Treaty Organization (SEATO) and ANZUS Pacts, and in the hope of shoring up its alliance with the US, became involved in the Vietnam War. Between 1962 and 1972 it would send almost 60,000 personnel to Vietnam, including ground troops, naval forces and air assets, and would contribute large amounts of material to the war effort. While assisting the