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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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
U.S.–Austrian Peace Treaty (1921) for a US-Austrian cooperation not under the strict supervision of the League of Nations. As a result, the US government embarked on a path of partially assisting the government of the Austrian Republic to ease the burden of war reparations imposed in the Treaty of St. Germain. The treaty was supplemented by a treaty signed in Washington on November 26, 1924, which provided for the establishment of a mixed US-Austrian-Hungarian commission to decide amount of reparations to be paid by the Austrian and Hungarian governments to the US. U.S.–Austrian Peace Treaty (1921) The U.S.–Austrian Peace Treaty is a peace treaty