The United States military was involved in the Korean War from 1950 until 1953. The conflict originally broke out as a civil war between the communist forces of North Korea, supported by the Soviet Union and People's Republic of China, and the American-aligned forces of South Korea. With the invasion of the south of the peninsula by communist forces in 1950, a UN intervention led by the United States, but comprising countries such as the UK, Canada, and France, among others, was deployed to repel the attack and defend the sovereignty of the South Korean state.
The war would last for three years and claim the lives of over 800,000 military personnel and around one and a half million civilians. While a peace treaty was agreed between the two sides in 1953, the South's dictator, Syngman Rhee, refused to sign it and the two sides are technically still at war with a de facto ceasefire in place. The division of Korea continues to be an issue of domestic and international importance. Due to the arbitrary nature of the peninsula's partition into two states, many families remain separated on either side of the demilitarized zone which acts as a border between the two countries. From a Western geopolitical perspective, the North remains a nuclear power and is considered by the United States and its Asian allies to be a serious security threat, whereas the South has become one of the world's largest and most advanced economies, with growing cultural influence across the globe.
The beginning of the Cold War
The Cold War (1947-1991) is the name given to the geopolitical rivalry between the world's two economic and military superpowers in the aftermath of World War II: the United States and the Soviet Union. In spite of the heightened tensions during this period, the two sides never came into direct military conflict with each other, opting instead to fight a number of proxy conflicts in strategically important countries such as Germany, Cuba, Vietnam, Afghanistan, and also Korea. In the five years between the end of World War II in 1945 and the beginning of the conflict on the Korean peninsula, the relationship between the former allies had broken down.
The Soviet Union had emerged from the Second World War with a vastly expanded sphere of influence, with large swathes of Central and Eastern Europe under its control, and it was an ally of the communist victors in the Chinese Civil War in 1949. On the other hand, the United States, the world's pre-eminent economic power, began to formulate a doctrine of containment which justified massive packages of economic aid and military spending in order to halt the march of global communism. Korea became the key site of this ideological battle in the early 1950s, as the division of the peninsula into a communist north and U.S.-aligned south in the aftermath of WWII escalated into a full scale military conflict.
The origins of the conflict in Korea
The Korean peninsula had been colonized by Japan in the period from 1910 to 1945, but fell under Allied control following Japan's surrendered to the United States after the dropping of atomic bombs on Hiroshima and Nagasaki in August 1945. It is believed that one reason for these nuclear attacks was for the U.S. to win the Pacific War before the Soviets had time to mount an invasion of Japan, which would have likely led to its partition between the two powers (similar to Germany), giving the USSR more influence in the region. Instead, the U.S. became the sole occupier of Japan after the war, while Korea was split along the 38th parallel. The northern half of the peninsula became the Democratic People's Republic of Korea, a communist state aligned with the Soviet Union and Maoist China, while the south became the Republic of Korea, a U.S.-backed regime. The occupation of the two halves of the country was unpopular among many Koreans, with riots and protests breaking out in 1945, which led to increasingly authoritarian measures taken by the occupying forces to retain control.
Due to dissatisfaction with the joint control with the Soviets, the U.S. announced it held a general election under UN supervision to decide the fate of an independent Korea. With the boycott of the 1948 election by the Korean communists and Soviet authorities, the division of the country was solidified - the South received a new political constitution and elected its first president, Syngman Rhee, under conditions generally not viewed as free or fair. The North subsequently became a communist state, led by Kim Il-sung, the grandfather of current North Korean dictator, Kim Jong-un. Over the following two years, a communist insurgency would fuel instability in the South, while the two sides' militaries would sporadically clash along the border.
The outbreak of war in Asia
On June 25. 1950, the North Korean People's Army stormed across the border. The People's Army quickly overran the forces of the South, with the Southern government fleeing from the capital, Seoul. U.S. President Truman and his main military general, Douglas MacArthur, immediately turned to the United Nations to gain international support for South Korea. While votes at the UN Security Council are generally hard to pass as they require unanimous approval (meaning that every member has veto power), the Soviet Union was boycotting the council due to the Chinese seat being given to the Republic of China (based in Taiwan) instead of the People's Republic of China (based on the mainland), the votes to support the South were passed. With the support of UN and U.S. forces, South Korea was able to slow the advance of the communist forces, however, by August of 1950, the North controlled virtually all of the peninsula apart from a small area known as the Pusan perimeter, around the southeastern port city of Pusan.
General MacArthur decided that, in order to break out of the perimeter, they needed to land an invasion force behind enemy lines near to the capital, Seoul. U.S. forces began this amphibious invasion at the port of Incheon on September 15, and made rapid advances due to the North Korean forces now being spread across two fronts. Within ten days, the U.S. had retaken Seoul and began an advance into the North. By October, the UN forces had repelled all North Korean soldiers back north of the 38th parallel and were advancing northwards to the border with China. MacArthur favored a strategy that would destroy the North's positions in China in order to prevent future attacks. This aggressive strategy led to the People's Republic of China joining the war on the side of the North, with Chinese soldiers first engaging the UN troops in battle on October 25.
Stalemate and the end of the war
The entry of Chinese forces into the conflict drastically shifted the balance of power back toward the communists and, by January of 1951, the two sides were back at the border between the North and South. The Chinese retook Seoul on January 5. and China's leader, Mao Zedong, encouraged by this progress, widened the aims of the offensive to now focus on taking the entire Korean peninsula for the communists. While they had been successful in recapturing the North's territory, the offensive in the Spring of 1951 made little gains, and fatalities mounted rapidly. On the U.S. side, General MacArthur was increasingly viewed as a liability for his 'victory at all costs' attitude and his willingness to defy the orders of President Truman. MacArthur was relieved of his duties as commander of the forces in Korea on April 11th. The war now entered a phase of attrition, with high casualty counts but few outright victories. Both sides began to acknowledge the stalemate that had been reached, with negotiations to end the war beginning in July 1951, although no ceasefire was called.
It would take over two years before the armistice agreement between both sides would be signed on July 27, 1953. Fighting continued throughout 1951 and 1952, but without the rapid advances and territorial exchanges that had characterized the first year of the war. Negotiations proceeded slowly as neither side could agree on many issues, including the exchange of prisoners of war, security guarantees for either side, or a roadmap for potential future reunification. The Chinese mounted a final large offensive in late 1952 to try to encourage incoming President Dwight D. Eisenhower to agree to a peace agreement, but in fact the Americans had already committed to the idea. Additionally, the resolve of the communists was severely weakened by the death of Soviet leader Joseph Stalin in March 1953. On July 27th, the UN command, North Koreans, and Chinese signed the peace agreement, with the South abstaining. In spite of Syngman Rhee's dissention, the agreement brought fighting in the war to a close.
The legacy of the Korean War
In the United States, the Korean War is sometimes referred to as the 'forgotten war', due to the relative lack of cultural memory of the war among the general populace, particularly in comparison to World War II and the Vietnam War. In spite of this, the war continues to be important both from the perspective of the lasting physical and emotional damage caused by the conflict, as well as the unresolved geopolitical tensions which persist in the Korean peninsula and its neighbors to this day. Lasting popular culture references left by the war from an American perspective include the popularity of the 1980s television show M*A*S*H, which still holds the record for having the most viewed tv episode in U.S. history, while the Chinese film The Battle at Lake Changjin is the highest-grossing non-English film of all time. The war continues to be portrayed widely in South Korean films and tv shows, due to its severe impact on the country.
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