8.1 Postwar Foreign Policy

Containment and the Cold War

After WWII, the U.S. adopted containment to stop Soviet/communist expansion. The Truman Doctrine (1947) pledged aid to nations resisting communism (Greece/Turkey). The Marshall Plan rebuilt Western Europe economically to prevent communist influence. NATO (1949) formed a military alliance against the USSR, deepening the bipolar Cold War divide.

Hot Spots: Korea and the Arms Race

Containment led to the Korean War (1950-53), a stalemate ending near the original border, showing limits of U.S. power. The Cold War fueled an arms race and nuclear deterrence strategy (mutually assured destruction). NSC-68 shaped policy, calling for a massive military buildup to counter perceived Soviet threats globally.

Domestic Fallout and Vietnam

Fear of communism sparked the Second Red Scare, McCarthyism, and loyalty investigations (HUAC). Containment logic escalated U.S. involvement in Vietnam, based on the domino theory — fear that one nation falling to communism would trigger neighbors to follow, justifying deep, costly military commitment despite growing public opposition.

Key terms

Containment

U.S. Cold War policy aimed at stopping the spread of communism without direct war with the USSR.

Truman Doctrine

1947 policy pledging U.S. aid to nations resisting communism, starting with Greece and Turkey.

Marshall Plan

U.S. economic aid program to rebuild Western Europe and prevent communist influence.

Domino theory

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

NSC-68

1950 policy paper urging a massive U.S. military buildup to contain Soviet expansion globally.

Try an AP-style question

The Truman Doctrine (1947) pledged U.S. support to…

1. countries seeking colonies
2. the Soviet Union's allies
3. nations resisting communism
4. isolationist nations