8.8 The Vietnam War

Cold War Roots and Escalation

U.S. involvement grew from containment policy and the domino theory, fearing communism would spread across Southeast Asia if Vietnam fell. After the Gulf of Tonkin incident (1964), Congress passed the Gulf of Tonkin Resolution, giving President Johnson broad war powers without a formal declaration of war, leading to major troop escalation.

A Divisive, Unwinnable War

The Tet Offensive (1968) shocked Americans, undermining official claims of progress and fueling the credibility gap. Rising casualties, the draft, and graphic television coverage fueled a growing antiwar movement, campus protests, and generational conflict, deeply dividing the nation over the war's morality and purpose.

Withdrawal and Legacy

Nixon pursued Vietnamization, gradually withdrawing U.S. troops while South Vietnamese forces took over combat roles; secret bombings expanded into Cambodia and Laos. The Paris Peace Accords (1973) ended U.S. involvement, and Saigon fell in 1975. The war left lasting distrust of government and shaped the War Powers Act (1973).

Key terms

Domino theory

Belief that if one nation fell to communism, neighboring nations would follow, justifying U.S. intervention in Vietnam.

Gulf of Tonkin Resolution (1964)

Congressional act giving Johnson broad authority to wage war in Vietnam without a formal declaration.

Tet Offensive (1968)

Surprise attack by North Vietnam/Viet Cong that damaged U.S. public confidence despite being a military failure for them.

Vietnamization

Nixon's policy of withdrawing U.S. troops while transferring combat responsibilities to South Vietnamese forces.

Paris Peace Accords (1973)

Agreement ending direct U.S. military involvement in Vietnam; fighting continued until Saigon fell in 1975.

Try an AP-style question

The Gulf of Tonkin Resolution (1964)…

1. ended U.S. involvement in Vietnam
2. gave Johnson broad power to escalate the war
3. declared war on North Vietnam
4. banned the draft