On 8 September 1945, 72,000 American forces of Lieutenant General John R. Hodge's XIV Corps arrived in Korea. The American troops quickly occupied their zone south of the 38th Parallel and established the U.S. Army Military Government in Korea (USAMGIK).
The Cold War had a profound impact on Korea's future. From the outset, Korea's future as a unitary nation depended on the ability of the United States and the Soviet Union to maintain friendly relations. But Washington and Moscow began to implement unilateral policies of zonal reconstruction that completely disregarded the interests of the other. The two superpowers established a joint commission in 1946 to produce an independent, unified Korea. Almost from the beginning, however, the commission had little chance of success.
From 1946 on, the United States and the Soviet Union seemed determined to establish client states in their zones that would share their respective ideological and political goals. By 1948 the United Nations (UN), with the active support of the United States, sanctioned elections in Korea that were to produce a free and independent state. Since the Soviets had already indicated that they would not allow such elections to be held in the north, this essentially meant the establishment up a separate government in the south. On 10 May 1948, elections in the south occurred. With all the leftists and most moderates already excluded from the political process, Syngman Rhee and the rightists claimed victory. Three months later, on 15 August, South Korea was formally established with Rhee as president.
The course of events in South Korea brought a prompt response from North Korea. On 9 September 1948 North Korea, led by Kim Il Sung, was proclaimed. On 12 December 1948 the UN recognized the ROK as the only lawfully constituted government on the Korean Peninsula.
South Korea faced a guerrilla insurgency beginning in the fall of 1948, which began with a major rebellion in its own security forces. On 19 October 1948, some 2,000 troops rebelled at the port city of Yosu under communist instigation. The South Korean government ended most of the unrest by late October, but the rebellion was followed by numerous small guerrilla actions designed to topple the Rhee government, although most of them had been ended by May 1950. In the meantime, tensions mounted as U.S. and Soviet troops turned over control of the peninsula to their Korean counterparts.
During 1949, border skirmishes between North and South Korea escalated. The presence of occupation forces had prevented a military confrontation between the two Koreas, but the Soviets had announced that their troops would be withdrawn by the end of 1948, and the United States had begun a quiet pullout, which it completed in June 1949. By now the lines of future conflict were essentially drawn.
On 25 June 1950, North Korea launched a well-planned, full-scale invasion of South Korea. Only the decision of President Harry S. Truman to commit U.S. troops to the Korean War under UN auspices saved South Korea from defeat. Truman and his advisors were convinced that the outbreak of war in Korea was orchestrated by Moscow. After three years of a bloody war of attrition, on 27 July 1953 the Korean Armistice Agreement was signed by North Korea, the People's Republic of China (PRC), and U.S. representatives. Rhee refused to sign. Although the communists had argued for the restoration of the 38th Parallel boundary, the military line became the armistice line, with a demilitarized zone created to extend 2 kilometers along each side of it.
The most important diplomatic action to come out of the war was the 1 October 1953 signing of the Mutual Defense Treaty between South Korea and the United States. Rhee had desperately wanted this arrangement, which in fact was part of a larger promise for extensive military and economic assistance that Washington had already given to him in return for his acceptance—if not approval—of the armistice.
The Mutual Defense Treaty had tremendous implications for both South Korea and the United States. The two nations were now bound together as never before, and the United States was legally and publicly committed to the defense of South Korea. As part of that defense, significant numbers of American ground, air, and naval forces would be permanently stationed in South Korea. The U.S. military commitment also implied a major political and economic commitment to South Korea as well.
Since the mid-1980s, however, the international and regional context of South Korean–U.S. relations has undergone great and possibly fundamental changes, at a rate outpacing the ability of officials to deal with them. Domestic changes in South Korea, particularly rapid economic growth, political democratization, and generational change, have triggered a profound transformation in the relationship between the two countries. These changes have encouraged new stirrings of nationalism among Koreans. At the same time, the near-collapse of the North Korean economy and the progress of inter-Korean relations have also affected South Korean–U.S. relations. Many South Koreans no longer regard North Korea as a serious threat, and their perception of the United States, in particular the American military presence, has become jaded. As it has grown in economic wealth and worked toward military self-sufficiency, South Korea has chafed in its role as a junior partner of the United States and has been seeking greater independence within the alliance.
South Korea's fear of the military threat from North Korea has rapidly declined since early 1998, when South Korean President Kim Dae Jung was inaugurated and soon initiated the so-called sunshine policy of rapprochement with Pyongyang, producing a great debate in South Korean society over the U.S. military presence. The 36,500 U.S. troops guarding against another North Korean invasion have been increasingly perceived as a social irritant and a remnant of the now almost-forgotten Cold War. Recent standoffs between Washington and Pyongyang over North Korea's nuclear ambitions have also adversely affected the already-strained relations between Seoul and Washington. Seoul's sunshine policy to actively engage Pyongyang might well foreshadow the sunset of the South Korean–U.S. alliance. There remained a widespread and entirely natural longing in South Korea to end the threat from North Korea and to jettison the burdens that this entails.
In terms of domestic politics, from its inception the South Korean government was dominated by strong, autocratic rulers exercising virtually unchecked powers. Rhee became increasingly dictatorial and corrupt until a student-led revolt forced him to resign in April 1960. A year later his moderate successor, John M. Chang, was ousted by a military coup led by Major General Park Chung Hee, whose iron-fisted rule ended abruptly with his assassination in October 1979. Park's successor, Major General Chun Doo Hwan, went on to create another authoritarian regime. Under Park and Chun, South Korea experienced dramatic industrial development and became an economic powerhouse. But the discrepancy between economic prosperity and political backwardness created growing public discontent.
Near the end of Chun's regime, South Koreans demanded an end to military rule. The June Resistance of mid-1987 was a critical turning point for the South Korean government, as it sought to abolish authoritarianism and embrace a civil, democratic society and the rule of law. In the 1990s, under Presidents Roh Tae Woo, Kim Young Sam, and Kim Dae Jung, South Korea's burgeoning democracy threw off the last vestiges of military rule. But its once-famed economy, the world's eleventh-largest, collapsed in 1997 during the Asian financial crisis, forcing Seoul to seek a bailout loan from the International Monetary Fund (IMF). Contrary to many predictions at the time, the recovery from the economic crisis came quickly and forcefully, once again producing a groundswell of national confidence. Jinwung Kim
Hart-Landsberg, Martin. Korea: Division, Reunification, and U.S. Foreign Policy. New York: Monthly Review Press, 1998.; Kim, Jinwung. 'Little Brother' Grows Up and Talks Back." Korea Monitor 1(3) (October 2003): 16–26.; Kim, Jinwung. "Can the U.S. and South Korea Forge a More Equal Alliance?" Korea Monitor 1(5) (December 2003): 38–47.; Lee, Ki-baik. A New History of Korea. Cambridge: Harvard University Press, 1984.