The United States, North and South Vietnam and the Provisional Revolutionary Government sign an agreement ending direct US involvement in the war.
The last US combat units leave South Vietnam under the terms of the Paris Peace Accords.
Arab oil producers impose an embargo on countries supporting Israel, causing world oil prices to soar.
U.S. President Richard Nixon's visit opens the way to normalised relations between the United States and China.
North Vietnam launches a large conventional offensive on three fronts in the South, including prolonged fighting at Quảng Trị.
The United States carries out intensive B-52 bombing of Hanoi and Haiphong for twelve days, known in Vietnam as the "Điện Biên Phủ in the air".
Chinese naval forces clash with the South Vietnamese navy and take control of all of the Paracel Islands.