1972 in the Vietnam War the number of air raids against North Vietnam during all of 1971. Prime Minister Lon Nol declared President of Cambodia. Unlike the former Cambodian leader, Norodom Sihanouk, Lon Nol was a U.S. ally. The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam. The Khmer Rouge bombarded with artillery Phnom Penh, the capital city of Cambodia, killing more than 100 civilians. This was the heaviest attack on Phnom Penh since the Cambodian Civil War began in 1970. The United States boycotted peace negotiations in Paris with the North Vietnamese, citing
Role of the United States in the Vietnam War of Defense & Joint Staff, FOIA Requester Service Center "Under Eisenhower" "Under Kennedy" "Under Johnson" "Under Nixon" "Under Ford" Role of the United States in the Vietnam War The role of the United States in the Vietnam War began after World War II and escalated into full commitment during the Vietnam War from 1955 to 1975. The U.S. involvement in South Vietnam stemmed from 20 long years of political and economic action. These had the common incentive of ending the growing communist domination in Vietnam. At the time, French forces, allies of the U.S., were backed by America — President