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 The U.S. 101st Airborne Division left South Vietnam, the last U.S. ground combat division to be withdrawn from South Vietnam.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) U.S.–Austrian Peace Treaty (1921) The U.S.–Austrian Peace Treaty is a peace treaty between the United States and Austria, signed in Vienna on August 24, 1921, in the aftermath of the First World War. This separate peace treaty was required because the United States Senate refused to advise and consent to the ratification of the multilateral Treaty of Saint-Germain-en-Laye of 1919. Ratifications were exchanged in Vienna on November 8, 1921, and the treaty became effective on the same day. The treaty was registered in "League of Nations Treaty Series" on November 22, 1921. During the First World War, Austria – which