U.S. History

The Korean Police Action, as the United Nations called it, was the hot war during the cold war.

The calendar announced the year was 1950. World War II was in the rearview mirror. The United Nations was established to avoid another global conflict, and Americans were weary of fighting in foreign countries and were settling in for what was hoped to be an extended period of peace. However, peace was not to be. The world had been divided into two camps: what many called the Free World and the Soviet Union with its communist allies. A prime example of this divide was the separation of the Korean Peninsula into North Korea, backed by the Soviet Union and communist China, and South Korea (Republic of Korea-ROK), backed by the United States.

The Korean War Was an Unwanted Conflict

The Second World War had been tremendously costly in human lives and military capability. Few in the United States were enthusiastic about another conflict. At the conclusion of World War II, America had significantly downsized its military and consequently failed to appreciate the magnitude of growing tensions in the Pacific. Nonetheless, that tension resulted in open hostilities when, on June 25, 1950, North Korea invaded South Korea with the goal of unifying Korea under communist rule. The North Korean attack was a coordinated assault along a line from coast to coast of 90,000 troops in seven infantry divisions. The North Korean People’s Army (NKPA) rapidly moved south, capturing Seoul and forcing a retreat of the ROK army, numbering roughly 22,000 combat-ready troops and a US advisor group (Korean Military Advisory Group – KMAG) of 500 US Army trainers stationed in South Korea. Realizing the US and ROK fighters were in trouble, on July 1, General Douglas MacArthur deployed to South Korea a small contingent of 400 soldiers from the 24th Infantry Division stationed in Japan.

By the end of July, the KMAG had been reinforced by 15,000-20,000 soldiers from the 24th, 25th, and 1st Cavalry Divisions. However, in less than six weeks, the NKPA pushed the ROK and American ground troops back to a small region known as the Pusan Perimeter, roughly 100 miles North to South and 50 miles wide from east to west at the southern tip of the Korean Peninsula. The ROK and US forces established a defensive line at the Pusan Perimeter.

In August 1950, the US pushed for more troops to the ROK to bolster the Pusan Perimeter, and by early September, the number of US forces rose to 90,000. On September 15, against the views of many military strategists, MacArthur carried out an amphibious landing of 80,000 Marines at the port of Inch’ŏn on the West Coast of South Korea west of Seoul. In his essay “The Korean War: Everything You Need to Know,” Gregg Brazinsky explained: “The harbor at Inch’ŏn was known for its dangerous tides that at their worst could destroy entire flotillas of ships. But MacArthur managed to land a fleet of 261 ships and 80,000 marines at this port while hardly sustaining any losses of either troops or ships. The DPRK lines were thus cut in two and quickly disintegrated.”

The landing at Inch’ŏn and the breakout of South Korean and American troops from the Pusan Perimeter resulted in a reversal of the gains made by the NKPA, driving them back to the 38th parallel. When it was clear that the NKPA could not hold and was being pushed back not just into North Korea but across the North Korea-China border, the Chinese People’s Liberation Army joined the conflict. However, by then, United Nations forces, made up of the militaries from 15 nations including Britain, Canada, Australia, and France along with US soldiers, were also engaged. Americans made up more than 50% of the UN contingent. Nonetheless, Chinese soldiers pouring over the border along with the NKPA caught the US and allied forces by surprise. Once again, Americans were driven South, and communist forces captured Seoul. UN and American forces eventually drove the Chinese and North Koreans back to the 38th parallel, where the fighting stalled between 1951 and 1953.

The End of the War

During this period, both forces fortified their positions and entered into negotiations to cease hostilities. For two years, fighting along the battle line continued with significant American casualties. However, eventually, the Chinese and North Koreans also grew tired of the enormous losses they were sustaining. In the end, political changes in the United States and in the Soviet Union led to the signing of a peace agreement on July 27, 1953.

General Dwight Eisenhower became the US president, and the communists believed he would be more inclined to escalate the fighting, perhaps even attacking the Chinese mainland. Consequently, China became more enthusiastic to negotiate an end to the fighting. On the communist side, there was a major change as well. The Soviet leader, Joseph Stalin, had been pressuring Chinese leadership to take stay in the fight. However, Stalin died in March 1953. The pressure was off, and the People’s Republic of China demonstrated a willingness to come to the negotiating table.

The Korean War, or “police action” as the UN labeled the conflict, was a valuable learning experience for the US. Never again could America become complacent with its national security. Threatening and dangerous adversaries would be standing ready to do America harm. As the “cold war” raged, a hot war would be just around the corner.

1. The Korean War was fought from June 1950 to July 1953. The North Koreans were supported by the Soviet Union and communist China, and the South Koreans were supported by the United States and the United Nations.
2. The peace treaty and the end to the war came after both sides stopped making real progress, despite all the deaths. Political changes both in the Soviet Union and the United States changed the situation, as well.
3. After World War II, the US shrank its military and didn’t want to get involved in any more foreign wars. The Korean War taught America that it had to take the actions of foreign nations and the effects of those actions on US national security seriously.