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 War Task Force in Phước Tuy Province. Australia, with decades of experience from both the Malayan Emergency and its AATTV role in 1962, recognised the necessity of a true counter-insurgency, which relied on providing village-level security, establishing civilian trust and economic incentives and improving ARVN capabilities. This brought Australian commanders into conflict with Westmoreland's conventional attrition warfare approach, since Australian ground forces were required to follow US doctrine. Nevertheless, Australian forces were generally the most capable at counter-insurgency, and they helped to train Regional Forces despite being under significant doctrinal constraints. Some 10,450 Filipino troops were dispatched to South Vietnam and