The Korea Decision

This flow traces Truman’s response to the invasion of South Korea and his effort to keep the conflict limited.

increasingBearing stren­gth in each eventdecreasing

Invasion Report

Invasion Report A Sudden Crisis Truman learned that North Korean forces had crossed the 38th parallel. Reports soon described the collapse of South Korean defenses and the danger to Seoul. Decision Context The invasion appeared to challenge the postwar order and the authority of the United Nations.

U.N. Response

U.N. Response Collective Action Truman’s administration secured United Nations support for force against North Korea and committed American air and naval power. Escalation When MacArthur reported that air and sea power alone could not hold the line, Truman authorized ground troops.

The Pusan Perimeter

The Pusan Perimeter Retreat Outnumbered American and South Korean troops fell back through intense heat, disease, and heavy fighting. They established a defensive line around Pusan. Resolve Truman continued the commitment despite rising casualties and doubts about whether the line could hold.

Inchon and the Northward Advance

Inchon and the Northward Advance Reversal Truman backed MacArthur’s risky landing at Inchon. Its success reversed the campaign and led U.N. forces north across the 38th parallel. New Danger The advance brought the possibility of Chinese intervention into immediate focus.

Choosing Limited War

Choosing Limited War Chinese Intervention A massive Chinese counteroffensive forced U.N. forces into a difficult retreat. Truman rejected calls to expand the war onto Chinese territory or use nuclear weapons. Principle He chose to limit the conflict, protecting civilian control and avoiding a wider war despite fierce criticism.

June 25, 1950

June 25–30, 1950

July–August 1950

September–October 1950

November 1950–1951