Foreign Intervention in Korea

35.3.4: Foreign Intervention in Korea

As the conflict between South Korea and North Korea reflected the international tensions of the Cold War, the U.S. military forces supported South Korea under the auspices of the UN while Chinese forces backed North Korea with the Soviet Union providing materiel and strategic help.

Learning Objective

Compare involvement of the U.S., USSR, and China in the Korean War

Key Points

  • On June 25, 1950, the United Nations Security Council unanimously condemned the North Korean invasion of the Republic of Korea with UN Security Council Resolution 82. On June 27, 1950, the Security Council published Resolution 83 recommending member states provide military assistance to the Republic of Korea. On the same day, President Truman ordered U.S. air and sea forces to help the South Korean regime.
  • U.S. Secretary of State Dean Acheson and President Truman agreed that the United States was obligated to act, paralleling the North Korean invasion with Adolf Hitler’s aggression in the 1930s with the conclusion that the mistake of appeasement must not be repeated. However, Truman later acknowledged that he believed fighting the invasion was essential to the American goal of the global containment of communism.
  • In September 1950, Zhou Enlai warned the United States that China was prepared to intervene in Korea if the U.S. crossed the 38th parallel. By October 1950, the UN Command repelled the Korean People’s Army north past the 38th parallel and the ROK Army crossed after them into North Korea. China justified its entry into the war as a response to “American aggression in the guise of the UN.”
  • Although the Soviet Union agreed upon the Chinese intervention and supported the North Korean and Chinese forces with material and military experts, Stalin made it clear that Soviet forces themselves would not directly intervene.
  • From July 1951 to the end of the war in 1953, the UN Command and the Chinese People’s Volunteer Army fought but exchanged little territory. The stalemate held although large-scale bombing of North Korea continued. The UN Command forces’ goal was to recapture all of South Korea and to avoid losing territory. The PVA and the KPA attempted similar operations and later effected military and psychological operations in order to test the UN Command’s resolve to continue the war.
  • The U.S. forces were not the only international units fighting in the Korean War under the auspices of the UN. The United Nations Command was in fact the unified command structure for the multinational military forces supporting South Korea. The United Nations Command and the Chinese-North Korean Command signed the Korean Armistice Agreement on July 27, 1953, ending the heavy fighting.

Key Terms

Korean Demilitarized Zone
A highly militarized strip of land running across the Korean Peninsula. It was established at the end of the Korean War to serve as a buffer zone between the Democratic People’s Republic of Korea (North Korea) and the Republic of Korea (South Korea). It is a de facto border barrier that divides the Korean Peninsula roughly in half, created by agreement between North Korea, China, and the United Nations in 1953.
United Nations Command
The unified command structure for the multinational military forces supporting South Korea during the 1950-1953 Korean War.
Korean War
A 1950 – 1953 military conflict that began when North Korea invaded South Korea. The United Nations, with the United States as the principal force, came to the aid of South Korea. China came to the aid of North Korea, and the Soviet Union gave some assistance.

 

U.S. Intervention with UN Support

On June 25, 1950, the United Nations Security Council unanimously condemned the North Korean invasion of the Republic of Korea with UN Security Council Resolution 82 (the Soviet Union boycotted the UNSC at the time). On June 27, 1950, the Security Council published Resolution 83 recommending member states provide military assistance to the Republic of Korea. On the same day, President Truman ordered U.S. air and sea forces to help the South Korean regime.

U.S. Secretary of State Dean Acheson and President Truman agreed that the United States was obligated to act, paralleling the North Korean invasion with Adolf Hitler’s aggression in the 1930s with the conclusion that the mistake of appeasement must not be repeated. Several U.S. industries were mobilized to supply materials, labor, capital, production facilities, and other services necessary to support the military objectives of the Korean War. However, Truman later acknowledged that he believed fighting the invasion was essential to the American goal of the global containment of communism. In August 1950, the President and the Secretary of State obtained the consent of Congress to appropriate $12 billion for military action in Korea.

General Omar Bradley, Chairman of the Joint Chiefs of Staff, was faced with re-organizing and deploying an American military force that was a shadow of its World War II counterpart. Acting on Acheson’s recommendation, President Truman ordered General MacArthur to transfer material to the Army of the Republic of Korea while giving air cover to the evacuation of U.S. nationals. The President disagreed with advisers who recommended unilateral U.S. bombing of the North Korean forces and ordered the U.S. Seventh Fleet to protect the Republic of China (Taiwan), whose government asked to fight in Korea. The United States denied ROC’s request for combat lest it provoke a communist Chinese retaliation. Because the United States sent the Seventh Fleet to “neutralize” the Taiwan Strait, Chinese Prime Minister Zhou Enlai criticized both the UN and U.S. initiatives as “armed aggression on Chinese territory.”

In September, MacArthur received the top secret National Security Council Memorandum from Truman reminding him that operations north of the 38th parallel were authorized only if “at the time of such operation there was no entry into North Korea by major Soviet or Chinese Communist forces, no announcements of intended entry, nor a threat to counter our operations militarily.” Just three days later, Zhou Enlai warned the United States that China was prepared to intervene in Korea if the United States crossed the 38th parallel. By October 1950, the UN Command repelled the Korean People’s Army northwards past the 38th parallel and the ROK Army crossed after them into North Korea. MacArthur made a statement demanding the KPA’s unconditional surrender. On October 7, with UN authorization, the UN Command forces followed the ROK forces northwards. The X Corps landed at Wonsan (in southeastern North Korea) and Riwon (in northeastern North Korea), already captured by ROK forces. The Eighth U.S. Army and the ROK Army drove up western Korea and captured Pyongyang city, the North Korean capital, on October 19, 1950. At month’s end, UN forces held 135,000 KPA prisoners of war.

U.S. Marine guards North Korean POWs aboard ship, 1951, author unknown.

U.S. Marine guards North Korean POWs aboard ship, 1951, author unknown. The treatment of prisoners of war and their repatriation was a complicated issue in the Korean War. Nominally, both the Communists and United Nations forces were committed to the terms of the 1949 Third Geneva Convention regarding the treatment of POWs. However, both sides applied exceptions and the negotiations regarding POWs were contentious and difficult.

Taking advantage of the UN Command’s strategic momentum against the communists, General MacArthur believed it necessary to extend the Korean War into China to destroy depots supplying the North Korean war effort. President Truman disagreed and ordered caution at the Sino-Korean border.

Chinese Intervention with Soviet Support

China justified its entry into the war as a response to “American aggression in the guise of the UN.” In August 1950, Zhou Enlai informed the UN that “Korea is China’s neighbor” and “the Chinese people cannot but be concerned about a solution of the Korean question.” Thus, through neutral-country diplomats, China warned that in safeguarding Chinese national security, they would intervene against the UN Command in Korea. President Truman interpreted the communication as an “attempt to blackmail the UN” and dismissed it.

October 1, 1950, the day that UN troops crossed the 38th parallel, was also the first anniversary of the founding of the People’s Republic of China. On that day, the Soviet ambassador forwarded a telegram from Stalin to Mao and Zhou requesting that China send five to six divisions into Korea, and Kim Il-sung sent frantic appeals to Mao for Chinese military intervention. At the same time, Stalin made it clear that Soviet forces themselves would not directly intervene.

There was considerable resistance among many Chinese leaders, including senior military leaders, to confronting the U.S. in Korea. Mao strongly supported intervention and Zhou was one of the few Chinese leaders who firmly supported him. In order to enlist Stalin’s support, Zhou and a Chinese delegation arrived in Moscow on October 10. Stalin did not agree to send either military equipment or air support until March 1951. Soviet shipments of materiel, when they did arrive, were limited to small quantities of trucks, grenades, machine guns, and the like. Immediately upon his return to Beijing on October 18, Zhou met with Mao and military leaders Peng Dehuai and Gao Gang. The group ordered 200,000 Chinese troops to enter North Korea.

After secretly crossing the Yalu River on October 19, the Chinese People’s Volunteer Army (PVA) 13th Army Group launched the First Phase Offensive on October 25, attacking the advancing UN forces near the Sino-Korean border. This military decision made solely by China changed the attitude of the Soviet Union. Twelve days after Chinese troops entered the war, Stalin allowed the Soviet Air Force to provide air cover and supported more aid to China. After decimating the ROK II Corps at the Battle of Onjong, the first confrontation between Chinese and U.S. military occurred on November 1, 1950. Deep in North Korea, thousands of soldiers from the PVA 39th Army encircled and attacked the U.S. 8th Cavalry Regiment with three-prong assaults—from the north, northwest, and west—and overran the defensive position flanks in the Battle of Unsan.

On December 16, 1950, President Truman declared a national emergency, which remained in force until September 1978. The next day, Kim Il-sung was deprived of the right of command of KPA by China. After that, the leading force of the war on the North Korean side became the Chinese army.

Stalemate and Armistice

From July 1951 to the end of the war, the UN Command and the PVA fought but exchanged little territory. The stalemate held although large-scale bombing of North Korea continued. Protracted armistice negotiations began in July 1951, but combat continued while the belligerents negotiated. The UN Command forces’ goal was to recapture all of South Korea and avoid losing territory. The PVA and the KPA attempted similar operations and later effected military and psychological operations to test the UN Command’s resolve to continue the war. The on-again, off-again armistice negotiations continued for two years, first at Kaesong, on the border between North and South Korea, and then at the neighboring village of Panmunjom. A major, problematic negotiation point was prisoner of war (POW) repatriation. The PVA, KPA, and UN Command could not agree on a system of repatriation because many PVA and KPA soldiers refused to be repatriated back to the north, which was unacceptable to the Chinese and North Koreans. In the final armistice agreement signed in July 1953, a Neutral Nations Repatriation Commission was set up to handle the matter.

U.S. Marines fighting in Seoul, Korea, 1950, author unknown.

U.S. Marines fighting in Seoul, Korea, 1950, author unknown. U.S. Marines engaged in street fighting during the liberation of Seoul, circa late September 1950. Note M-1 rifles and Browning Automatic Rifles carried by the Marines, dead Koreans in the street, and M-4 “Sherman” tanks in the distance.

 

In 1952, the United States elected a new president, and in November, the president-elect, Dwight D. Eisenhower, went to Korea to learn what might end the Korean War. With the United Nations’ acceptance of India’s proposed Korean War armistice, the KPA, the PVA, and the UN Command ceased fire with the battle line approximately at the 38th parallel. Upon agreeing to the armistice, the belligerents established the Korean Demilitarized Zone (DMZ), which has since been patrolled by the KPA and ROKA, United States, and Joint UN Commands.

United Nations Command

The U.S. forces were not the only international units fighting in the Korean War under the auspices of the UN. The United Nations Command (UNC) was in fact the unified command structure for the multinational military forces supporting South Korea. The first non-Korean and non-U.S. unit to see combat was No. 77 Squadron, Royal Australian Air Force, which began escort, patrol and ground attacks from Japan in July 1950. In August 1950, the British Commonwealth’s 27th Infantry Brigade arrived at Busan. Units from other countries of the UN followed in rapid succession, including Belgium, Canada, Colombia, Ethiopia, France, Greece, Luxembourg, the Netherlands, New Zealand, the Philippines, South Africa, Thailand, and Turkey. Denmark, India, Norway, and Sweden provided medical units. Italy provided a hospital, even though it was not a UN member. Iran provided medical assistance from the Iranian military’s medical service.

Attributions