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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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
1968 in the Vietnam War 1968 in the Vietnam War The year 1968 saw major developments in the Vietnam War. The military operations started with an attack on a US base by the Vietnam People's Army (NVA) and the Viet Cong on January 1, ending a truce declared by the Pope and agreed upon by all sides. At the end of January, the North Vietnamese and the Viet Cong launched the Tet Offensive. Hanoi erred monumentally in its certainty that the offensive would trigger a supportive uprising of the population. NVA and Viet Cong troops throughout the South, from Hue to the Mekong Delta, attacked