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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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
1967 in the Vietnam War Junction City was an 82-day military operation conducted by United States and Republic of Vietnam (RVN or South Vietnam) forces begun on February 22, 1967, lasting until May 14, 1967. It was the largest U.S. airborne operation since Operation Market Garden during World War II, the only major airborne operation of the Vietnam War, and one of the largest U.S. operations of the Vietnam War. Operation Union was a search and destroy mission in the Que Son Valley carried out by the 1st Marine Regiment to engage the PAVN 2nd Division. Launched on April 21, 1967, the operation ended May