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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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
1973 in the Vietnam War by North Vietnam. Three C-141A transports flew to Hanoi, North Vietnam, and one C-9A aircraft was sent to Saigon, South Vietnam to pick up released prisoners of war. The first flight of 40 U.S. prisoners of war left Hanoi in a C-141A, later known as the "Hanoi Taxi" and now in a museum. From February 12 to April 4, there were 54 C-141 missions flying out of Hanoi, bringing the former POWs home. In Laos the government and the communist Pathet Lao signed a cease fire agreement. The agreement was violated frequently, but by the end of April most fighting