Korean War: 1950-1953 Conflict Overview

Model Diplomat Research Team · Last reviewed June 22, 2026

TL;DR

Armed conflict on the Korean Peninsula from 1950 to 1953 between North Korea and its communist allies and South Korea backed by a UN-led coalition.
Did the Korean War ever formally end?
Why could the UN Security Council authorize intervention?
Which countries fought under the UN Command?

History & Current AffairsUpdated June 22, 2026

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Timeline

25 June 1950
The Korean War began on , when forces of the Democratic People's Republic of Korea (DPRK) crossed the 38th parallel and invaded the Republic of Korea (ROK).
27 July 1953
The Korean Armistice Agreement was signed on at Panmunjom by representatives of the UN Command, the Korean People's Army, and the Chinese People's Volunteers.

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In July 1953, U.S. Army Lieutenant General William Harrison and North Korean General Nam Il signed the Korean Armistice Agreement at Panmunjom, halting active combat in the Korean War.

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Timeline

25 June 1950

The Korean War began on , when forces of the Democratic People's Republic of Korea (DPRK) crossed the 38th parallel and invaded the Republic of Korea (ROK).

27 July 1953

The Korean Armistice Agreement was signed on at Panmunjom by representatives of the UN Command, the Korean People's Army, and the Chinese People's Volunteers.

Research it like a delegate

The Korean War began on 25 June 1950, when forces of the Democratic People's Republic of Korea (DPRK) crossed the 38th parallel and invaded the Republic of Korea (ROK). The peninsula had been divided after World War II, with Soviet and U.S. occupation zones hardening into rival states by 1948.

Within days the UN Security Council passed resolutions condemning the invasion and authorizing member states to assist South Korea. These votes were possible because the Soviet Union was boycotting the Council over the seating of the Republic of China rather than the People's Republic of China. Sixteen countries ultimately contributed combat forces to the United Nations Command, established under U.S. leadership with General Douglas MacArthur as its first commander.

The war moved in dramatic phases. North Korean forces pushed the ROK and U.S. troops into the Pusan Perimeter by August 1950. MacArthur's amphibious landing at Inchon in September 1950 reversed the front, and UN forces advanced deep into the north toward the Yalu River. In late October 1950, the People's Republic of China intervened with "Chinese People's Volunteers," driving UN forces back below Seoul. Soviet pilots flew MiG-15s covertly in support. By mid-1951 the front had stabilized roughly along the 38th parallel, and the conflict became a war of attrition.

Armistice talks opened in July 1951 and dragged on for two years over prisoner repatriation and the demarcation line. The Korean Armistice Agreement was signed on 27 July 1953 at Panmunjom by representatives of the UN Command, the Korean People's Army, and the Chinese People's Volunteers. South Korean President Syngman Rhee refused to sign. The agreement created the Demilitarized Zone (DMZ) but no peace treaty followed, leaving the two Koreas technically still at war.

Casualty estimates vary widely; millions of Korean civilians and soldiers, and hundreds of thousands of Chinese and UN personnel, were killed or wounded. The war entrenched Cold War alliances in East Asia and shaped the U.S.–ROK Mutual Defense Treaty signed later in 1953.

Frequently asked questions

Did the Korean War ever formally end?

No. The 1953 armistice suspended hostilities but no peace treaty was concluded, so North and South Korea remain technically at war.

Why could the UN Security Council authorize intervention?

The Soviet Union was boycotting the Council in 1950 over the China seat and was therefore absent to veto the resolutions on Korea.

Which countries fought under the UN Command?

Sixteen states contributed combat forces, including the United States, United Kingdom, Canada, Australia, Turkey, France, the Philippines, and others, alongside the Republic of Korea.