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 dispatched as the Australian Army Training Team Vietnam (AATTV), also known as "the Team". The Australian military assistance was to be in jungle warfare training, and the Team comprised highly qualified and experienced officers and NCOs, led by Colonel Ted Serong, many with previous experience from the Malayan Emergency. Their arrival in South Vietnam during July and August 1962 was the beginning of Australia's involvement in the war in Vietnam. Relationships between the AATTV and US advisors were generally very cordial, but there were sometimes significant differences of opinion on the training and tactics that should be employed. For example,