Key Terms of the Vietnam War

Ngo Dinh Diem

U.S.-backed leader of South Vietnam (1954-1963); unpopular due to corruption and oppression, assassinated in a coup.

Domino Theory

Idea that if one country falls to communism, nearby countries will also fall, used to justify U.S. intervention in Vietnam.

Southeast Asia Treaty Organization (SEATO)

Alliance between the U.S. and allies (1954) to prevent communism from spreading in Southeast Asia.

Gulf of Tonkin Incident (1964)

Alleged attack by North Vietnamese boats on U.S. ships; led to increased U.S. involvement in Vietnam.

Gulf of Tonkin Resolution (1964)

Gave President Johnson authority to use military force in Vietnam without a formal declaration of war.

Credibility Gap

Growing public distrust of government claims about the Vietnam War, fueled by media coverage and official lies.

Hawks

Supported the war and wanted more military action.

Doves

Opposed the war, calling for peace and withdrawal.

Tet Offensive (1968)

Large-scale surprise attack by North Vietnam and Viet Cong; military failure for them but turned U.S. public against the war.

Election of 1968

Richard Nixon (Republican), Hubert Humphrey (Democrat), George Wallace (Independent); President Lyndon B. Johnson chose not to seek re-election due to war unpopularity.

Henry Kissinger

Nixon's National Security Advisor and later Secretary of State; helped negotiate the end of the Vietnam War.

Vietnamization

Nixon's policy to withdraw U.S. troops and shift the fighting to South Vietnamese forces.

Nixon Doctrine

Stated that the U.S. would support allies with money and weapons but not with large troop deployments.

Kent State (1970)

National Guard killed four students protesting the war, intensifying anti-war movements.

My Lai Massacre (1968)

U.S. troops killed hundreds of unarmed Vietnamese civilians, shocking the American public.

Pentagon Papers (1971)

Secret government documents leaked, exposing lies about U.S. involvement in Vietnam.

Paris Accords (1973)

Peace agreement that ended U.S. military involvement in Vietnam.

War Powers Act (1973)

Limited the president's ability to send troops into combat without congressional approval.