(1955-1975), military conflict in Vietnam between the U.S.-backed South Vietnamese government and the Communist-led guerrilla forces backed by North Vietnam. The war, the nation's longest, resulted in the loss of 58,000 American lives and was the first in which the United States failed to achieve its goals. The tonnage of bombs dropped on North Vietnam by the United States was greater than the total of that dropped on Germany, Italy, and Japan during World War II. The war left up to 10 million refugees and caused sharp divisions among the American people.
The Vietnam War followed the Indochina War (1946-54) in which the Vietnamese overthrew French rule when France tried to reestablish its colonial control of Southeast Asia after World War II. The Geneva Accords, which ended the struggle in 1954, created two nations: Communist-ruled North Vietnam and noncommunist South Vietnam. The accords required the holding of elections to determine what government a reunified Vietnam would have, but South Vietnam refused to comply. When North Vietnam, allied with the insurgent Vietcong, sought to overthrow the government of South Vietnam, the United States tried to stop it. American involvement has its roots in Harry S. Truman's decision to contain the spread of communism anywhere. Presidents Dwight D. Eisenhower, John F. Kennedy, and Lyndon B. Johnson carried on this policy, each one escalating U.S. involvement and the number of advisers and (after 1965) combat troops in Vietnam. The number of American troops exceeded 500,000 in 1968.
Congress passed the
Tonkin Gulf Resolution in 1964, authorizing the president to use military force without a formal declaration of war, and Johnson accordingly ordered bombing raids on North Vietnam. The
Tet Offensive of 1968 made it clear that the war would not end easily, and American opposition to the conflict increased at home. Although Richard M. Nixon ran for president with a promise to end the war, he actually expanded it by authorizing secret raids into Laos and an incursion into Cambodia. With each escalation, popular demonstrations (including one at
Kent State) and political pressure to end the war mounted.
Finally in 1973 a cease-fire was negotiated and U.S. troops were withdrawn. During 1973-74 the North Vietnamese continued to attack South Vietnam. In January 1975 a major attack was launched by the Vietcong, and the South Vietnamese government collapsed. The Communists then gained control of Vietnam and Cambodia and Laos, as well.
