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.
War in Vietnam (1945–46) War in Vietnam (1945–46) The War in Vietnam, codenamed Operation Masterdom by the British, and also known as Nam Bộ kháng chiến () by the Vietnamese, was a post–World War II armed conflict involving a largely British-Indian and French task force and Japanese troops from the Southern Expeditionary Army Group, versus the Vietnamese communist movement, the Viet Minh, for control of the country, after the unconditional Japanese surrender. The Indochina Wars are generally numbered as three: the first being France's unsuccessful eight-year conflict with the Vietminh nationalist forces (1946–1954); the second being the war for control of South Vietnam, featuring