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.
1972 in the Vietnam War this weekend." Anti-war demonstrators protested the bombing of North Vietnam throughout the United States. Hundreds of protesters were arrested. Several North Vietnamese MiG-17F fighter-bombers attacked United States Navy warships in the Battle of Đồng Hới. This was the first air attack on U.S. warships of the Vietnam War. One US destroyer was damaged. The U.S. navy sunk several motor torpedo boats and shot down several North Vietnamese war planes and also engaged shore batteries in North Vietnam. President Nixon announced that American troops would be reduced in numbers in South Vietnam from 69,000 on this date to 49,000 by 1