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.
1968 in the Vietnam War Khe Sanh began with an assault by the PAVN on a hill held by U.S. Marines. Khe Sanh is in northwestern Quảng Trị Province, near the Demilitarized Zone. The combatants were elements of the U.S. III Marine Amphibious Force (III MAF) and Army of the Republic of Vietnam (ARVN) against two to three PAVN division-size elements. NVA General Võ Nguyên Giáp later explained that his objective was to create a diversion to draw U.S. forces away from the populated areas of South Vietnam. Khe Sanh diverted 30,000 US troops away from the cities that would be the main targets of