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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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
Australian–Thai Peace Treaty at that point, but he urged his retention so long as the process for determining compensation claims lasted. He was not withdrawn until ratifications of the peace treaty were exchanged in May. In 1950 Thailand agreed to pay £6 million in compensation to the governments of Britain and Australia for wartime damage to their tin mining operations. The Australian share amounted to just over £1 million. Australian–Thai Peace Treaty The Australian–Thai Peace Treaty that ended World War II between Australia and Thailand was signed in Bangkok on 3 April 1946. The full title of the peace treaty is "Final Peace