Korean War Summary

  • Last updated on November 10, 2022

The first test of the U.S. policy of containment articulated in the Truman Doctrine, the Korean conflict escalated from a U.N.-led “police action” to a confrontation between the United States and the People’s Republic of China.

Summary of Event

At the end of World War II, Korea was a nation divided to allow for occupation by several members of the victorious Allied coalition. The so-called Hermit Kingdom, which had been under Japanese control for many years, was occupied by Soviet and U.S. forces, and the thirty-eighth parallel was set as a temporary line of demarcation. In their zone north of the parallel, the Soviets organized a communist regime, which was named the Democratic People’s Republic of Korea (North Korea) in 1948. An old-time communist, Kim Il Sung, was its first premier. In the south, various elements struggled for power until the party of the “father of Korean nationalism,” Syngman Rhee, won a United Nations-sponsored election. On August 15, 1948, Rhee became president of the Republic of Korea (South Korea). Korean War (1950-1953) [kw]Korean War (June 25, 1950-July 27, 1953) [kw]War, Korean (June 25, 1950-July 27, 1953) Korean War (1950-1953) [g]Asia;June 25, 1950-July 27, 1953: Korean War[03210] [g]North Korea;June 25, 1950-July 27, 1953: Korean War[03210] [g]South Korea;June 25, 1950-July 27, 1953: Korean War[03210] [c]Wars, uprisings, and civil unrest;June 25, 1950-July 27, 1953: Korean War[03210] [c]Cold War;June 25, 1950-July 27, 1953: Korean War[03210] Truman, Harry S. [p]Truman, Harry S.;Korean War MacArthur, Douglas [p]MacArthur, Douglas;Korean War Kim Il Sung Rhee, Syngman Eisenhower, Dwight D. [p]Eisenhower, Dwight D.;Korean War Stalin, Joseph [p]Stalin, Joseph;Korean War

(1) Main U.N. base. (2) Russian-Chinese naval installation. (3) Sept. 15, 1950, U.N. forces land. (4) Oct. 8, 1950, U.N. forces land. (5) Nov. 26, 1950, Chinese attack. (6) Dec. 9, 1950, U.N. forces evacuate. (7) July 27, 1953, armistice signed.





Both Korean governments were determined to achieve unification on their own terms. Large-scale guerrilla incursions into the south were supported by the North Koreans, and retaliatory raids by South Korean forces kept the divided country in a state of crisis. Despite this situation, U.S. troops were withdrawn in June, 1949, leaving behind only a small group of technical advisers. South Korea, whose army was small, ill-trained, and poorly equipped, faced an adversary that possessed an army of 135,000 men equipped with modern Russian weapons. North Korea also had between 150 and 200 combat airplanes.

Although South Korean leaders and some in the United States feared that North Korea might attack across the thirty-eighth parallel at any time, Secretary of State Dean Acheson Acheson, Dean gave further evidence of the United States’ disinterest by stating on January 12, 1950, that South Korea was not within the “defense perimeter” of the United States in the Pacific. Some authorities have suggested that Acheson’s remarks sent misleading signals to North Korea about the United States’ commitment to the security of South Korea. As yet, there is no documentary evidence to determine if these remarks had any effect on either North Korea or the Soviet Union. However, after the fall of the Soviet Union, historians found evidence to suggest that Joseph Stalin was deeply involved in planning the initial invasion and secretly supplied North Korea with Soviet pilots to counter U.S. airpower.

The attack came on June 25, 1950. North Korean armed forces—armored units and mechanized divisions supported by massed artillery—struck without warning across the demarcation line. Meeting only uncoordinated resistance, North Korean tanks were moving into the outer suburb of Seoul, the capital of South Korea, within thirty-six hours. Contrary to communist expectations, the United States reacted swiftly and with great determination. With U.S. encouragement, the United Nations United Nations;Korean War Security Council met in special session on the day of the attack. The Soviet Union was boycotting the council at the time, and a resolution calling for an immediate end to hostilities and withdrawal of North Korean forces to their former positions on the thirty-eighth parallel was passed unanimously.

When the United Nations resolution was ignored by North Korea, the Security Council convened on June 27, and adopted a resolution that recommended that members “of the United Nations furnish such assistance to the Republic of Korea as may be necessary to repel the armed attack.” President Harry S. Truman ignored recommendations of caution and acted to enforce the U.N. resolutions. On June 27, he committed U.S. air and naval forces to the conflict, as well as ground forces previously stationed in Japan.

These commitments were inadequate to stem North Korean advances. By the end of June, more than half of South Korea’s army had been destroyed, and U.S. units were forced to fight countless rearguard actions in a retreat southward. In early August, a defense perimeter was created around the important port of Pusan, and after intense fighting, a stable defense line was assured. As U.S. forces and contingents from fifteen other nations arrived, General Douglas MacArthur, commander in chief of the Far East and supreme commander of U.N. forces, decided to employ his troops not in a frontal offensive from Pusan but in a daring amphibious landing at Inchon, a west coast port just miles from Seoul. This brilliantly conceived but risky operation, launched on September 15, 1950, was a great success. The North Korean Army, threatened with encirclement, was forced to retreat back across the thirty-eighth parallel.

With the North Korean forces in retreat, the U.N. command was forced to make the single most important decision of the war: Should the retreating North Koreans be chased across the demarcation line? Pressed by public demands for total victory, the Truman administration cited the Security Council’s resolution and gave MacArthur authorization to pursue the North Korean troops across the thirty-eighth parallel. MacArthur already had decided to take this step. He was confident that the North Korean Army was effectively destroyed and that the Soviet Union and China would not risk a confrontation with U.N. forces led by the United States. The first crossing took place on October 1. United Nations and South Korean forces sped north, and by late November they were nearing the Yalu River boundary between North Korea and the People’s Republic of China.

The seesaw struggle was reversed once again by the entry of Chinese “volunteers” into the war. Chinese leaders had warned that they would not allow North Korea to be invaded and would come to the aid of their communist allies. U.S. intelligence services and MacArthur had dismissed these threats as rhetoric, but it soon became clear that Beijing was not bluffing. By late October, thousands of Chinese soldiers had crossed the Yalu River. A month later, they struck at the exposed flank and rear of MacArthur’s overextended armies. By early December, U.N. troops were again in headlong retreat, a withdrawal marked by great heroism but accounting for near-disaster for the U.N. forces.

In the United States, there was widespread fear of an expanded war in Korea. A Gallup poll estimated that 55 percent of the people in the United States believed that World War III had begun soon after the Chinese entry into the war. A new line was organized south of the thirty-eighth parallel, and through the remaining winter and early spring months, the lines fluctuated from south of Seoul to north of the thirty-eighth parallel. On April 11, Truman relieved MacArthur of his U.N. and U.S. commands, after MacArthur publicly questioned Truman’s prohibition on U.S. bombing of North Korean supply depots inside China. MacArthur’s support of a wider war against the People’s Republic of China had long been opposed by Truman, who feared an even greater conflict with the Soviet Union.

Military stalemate was finally reached in July, 1951. The conflict deteriorated into trench warfare, which was marked by indecisive but bloody fighting, at which the Chinese were particularly adept. The situation lasted for two cruel years. During this time, more than one million U.S. troops served in Korea. For much of this period, talks went on, seeking a cease-fire and armistice. On June 10, 1951, communist and U.N. delegations began negotiations, talks initiated by the North Koreans and welcomed by the majority of people in the United States. Most of the talks took place in the city of Panmunjom, located in the no-man’s-land between the two armies. The talks broke down repeatedly because of antagonism generated by North Korean accusations of germ warfare, disputes over prisoner-of-war exchanges, and other issues.

The stalemate was a source of mounting frustration in the United States, where it influenced both the rise of McCarthyism and the election of Republican Dwight D. Eisenhower to the presidency. Eisenhower won support by promising to go to Korea if elected. He kept his pledge, but the visit had no noticeable effect on the success of the peace talks. The North Korean and Chinese negotiators ultimately modified their position on forcible repatriation of prisoners, and an armistice agreement was signed at Panmunjom on July 27, 1953. It provided for a cease-fire and for withdrawal of both armies two kilometers from the existing battle line, which ran from coast to coast from just below the thirty-eighth parallel in the west to thirty miles north of it in the east. The agreement also provided for the creation of the Neutral Nations Supervisory Commission Neutral Nations Supervisory Commission to carry out the armistice terms. It further called for a political conference to settle all remaining questions, including the fate of prisoners who refused to return to their homelands. The political conference was never held, and relations between North and South Korea deteriorated because of each Korea’s claims on “unification” with the other.


The Korean war lasted three years and one month and took more than four million lives. There was little celebration in the United States at its conclusion. Upon signing the armistice in Panmunjom, U.S. commander Mark W. Clark Clark, Mark W. declared, “I cannot find it in me to exalt at this hour.” General Omar N. Bradley Bradley, Omar N. later observed that the conflict was “the wrong war, in the wrong place, at the wrong time, with the wrong enemy.” Some commentators did commend the United States’ resolve in containing communism and defending South Korea, but after the deaths of 54,000 troops, 100,000 wounded, 8,000 missing in action, and a cost of 22 billion dollars, most people in the United States were simply relieved that the fighting had ceased.

A symbol of the war’s unique status in history was the fact that the United States never formally declared war on North Korea or China. President Truman simply referred to the military hostilities in Korea as a United Nations “police action.” Because it was quickly followed by the United States’ protracted war in Vietnam, the Korean War soon became known as “the forgotten war.”

After the 1953 armistice, both the United States and the Soviet Union moved to fortify their positions on the Korean peninsula. Apart from isolated incidents at the border between the two Koreas, the two sides avoided open military conflict. Lacking an agreement to end hostilities, North and South Korea remained in a state of war, and more than a million troops were stationed guarding the 150-mile demilitarized zone. The United States continued to provide South Korea with military aid and stationed thousands of U.S. troops in the country. Korean War (1950-1953)

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Blair, Clay. The Forgotten War: America in Korea, 1950-1953. New York: Times Books, 1987. A well-researched, comprehensive examination of the origins and conduct of the Korean War. Index.
  • citation-type="booksimple"

    xlink:type="simple">Edwards, Paul M. The Korean War. Westport, Conn.: Greenwood Press, 2006. Part of the Daily Life Through History series, this book by a Korean War veteran and prolific scholar details the experiences of the individual troops fighting in Korea. Bibliographic references and index.
  • citation-type="booksimple"

    xlink:type="simple">Hastings, Max. The Korean War. New York: Simon & Schuster, 1987. An in-depth examination of military operations of the nations involved in the Korean War, from a British military historian. Chronology of the war, bibliography, index.
  • citation-type="booksimple"

    xlink:type="simple">Hoyt, Edwin P. The Day the Chinese Attacked: Korea, 1950. New York: McGraw-Hill, 1990. An investigation of the misperceptions and policy failures in the United States and China that led to the Chinese entry into the Korean War in October, 1950. Bibliography, index.
  • citation-type="booksimple"

    xlink:type="simple">James, D. Clayton, and Anne S. Wells. Refighting the Last War: Command and Crisis in Korea, 1950-1953. New York: Free Press, 1993. Provides a detailed examination of the conduct of the leadership, personalities, and viewpoints of President Truman, Douglas MacArthur, Matthew B. Ridgeway, Mark Clark, and Turner Joy. Index.
  • citation-type="booksimple"

    xlink:type="simple">Levine, Alan J. Stalin’s Last War: Korea and the Approach to World War III. Jefferson, N.C.: McFarland, 2005. In addition to detailed information on the military campaign in Korea itself, this text provides a global history of the Korean War, emphasizing its crucial place in Cold War history and the events relating to the war in Europe, Asia, and North America. Bibliographic references and index.
  • citation-type="booksimple"

    xlink:type="simple">Stokesbury, James L. A Short History of the Korean War. New York: William Morrow, 1988. A brief introduction to the sources, conduct, and outcome of the Korean War. Suggested readings, index.
  • citation-type="booksimple"

    xlink:type="simple">Whelan, Richard. Drawing the Line: The Korean War, 1950-1953. Boston: Little, Brown, 1990. Using declassified documents, this detailed examination of the war focuses mainly on the war’s roots and the effects of U.S. politics on the Korean War.

Rhee Is Elected President of South Korea

United Nations Korean Relief Agency Is Formed

Truman-MacArthur Confrontation

United States Enters the Vietnam War

North Korea Seizes the USS Pueblo

Categories: History