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US-South Korea Relations, 1945-

By Gregg Brazinsky

The US-South Korean relationship was one of America’s most important Cold War partnerships.

Table of Contents


The US-South Korean relationship was one of America’s most important Cold War partnerships. Today the Republic of Korea remains a critical ally and partner—strategically, economically, and politically. The relationship came about somewhat haphazardly through a hastily made agreement with the Soviet Union at the end of World War II to divide and occupy the Korean peninsula. The alliance between the two countries was forged in blood during the horrific Korean War (1950-1953) and has continued to evolve and deepen throughout the six decades since the war ended.

The Importance of South Korea to the United States

Although many Americans had virtually no knowledge of Korea before the end of World War II, the country became very important to the United States in a short time for several reasons. One of these was the enormous investment that Washington made in helping to create the Republic of Korea. Decisions made by the United States and the Soviet Union led to the division of the Korean peninsula first into separate zones of occupation and, in 1948, into separate states. During the US military occupation of South Korea (1945-1948), American forces played a critical role in determining which actors gained political power and which were excluded. Washington invested a great deal into assuring that conservatives rather than revolutionaries would control the country. As the Cold War between Moscow and Washington began to intensify during the late 1940s, Americans came to see South Korea as a bulwark against the spread of communism and as a buffer that separated Japan from the People’s Republic of China and the Soviet Union. Even during the years before the Korean War, the United States spent hundreds of million of dollars on reviving South Korea’s shattered economy and helping it to develop the fundamental prerequisites of statehood. The newly created ROK therefore immediately became important to American credibility both in Asia and around the world.

The fact that Korea was divided was another reason for its importance to the United States. As was the case in Germany, the division of a single national entity into separate “Free World” and communist states made the peninsula a natural showcase for the relative merits of the two systems to be demonstrated to the peoples of Asia. Americans expressed such concerns repeatedly, even before the Korean War broke out in June 1950. Americans therefore came to believe it was in their interests not only for South Korea to survive but also for it to thrive. If North Korea proved more successful at developing its economy or creating a political system that was admired internationally then the appeal of communism would be heightened. As the ROK experienced rapid economic growth during the 1960s and 1970s and then democratization during the 1980s and 1990s, Americans continued to point to South Korea as an example of what could be accomplished through free markets and alignment with the United States.

While South Korea has been of critical importance to Washington, American influence over the Republic of Korea has been vast and extended into almost every aspect of Korean life. Over the years military alliance, economic partnership and close political relations between the two countries have all made the United States an inevitable factor in shaping the course of events in South Korea.

The US-South Korea Political Relationship

America’s pivotal role in creating a separate South Korean state assured that the United States would also have a determinative influence over the country’s politics, at least during its early years. Yet America’s overall role in shaping South Korean politics has also been a very complicated one. While the United States has, on the one hand, often supported dictatorial regimes in Seoul, it has also sought in other ways to contribute to the country’s democratization.

During the US military occupation of southern Korea, Washington’s influence played an important role in helping Syngman Rhee gain influence and power. Rhee had spent much of the previous three decades in the United States lobbying on behalf of Korea’s independence from Japan. When the US military brought Rhee back to his motherland, its leadership was far from enamored of him. He could be obstinate and resistant to American pressure on many issues. At the same time, Rhee had genuine nationalist credentials and was strongly anti-communist. This was a somewhat rare combination in Korea during the years after World War II and made him too potentially valuable to ignore. Thus, as Rhee gained political ascendancy in southern Korea, the United States did little to interfere because it saw no viable alternative.

Throughout the 1940s and 1950s, America’s most pressing concern in Korea was security. This was true not only during the Korean War but also in its immediate aftermath when the possibility of another North Korean invasion seemed to loom large. In this context, Washington believed that if the ROK’s leadership wavered in its resistance to communism, the country could easily fall prey. Between 1948 and 1960, the United States saw little alternative but to support Syngman Rhee’s government despite its corrupt and autocratic character. Washington was supportive when Rhee was elected South Korea’s first president in 1948 and did not offer strong resistance when, in 1952, he forced a constitutional amendment through the legislature allowing him to seek additional terms in office. Although American officials did not trust the aging Korean leader, they also believed that South Korea was not truly ready to become democratic and feared that Rhee’s ouster would only lead to instability.

But if Americans did not see any alternatives to Rhee, they did try to encourage their emergence. They did this by helping to build up South Korean institutions that might one day produce more progressive leaders. In particular, they played a significant role in aiding the recovery of South Korea’s educational system during the 1950s and providing special training for top young South Korean bureaucrats and administrators who Americans hoped would one day govern the country in a more competent and efficient way.

Syngman Rhee was finally overthrown on April 19, 1960, in a student led revolution. Thousands of students joined in demonstrations throughout the country to protest an obviously fraudulent election held the previous month and the subsequent slaying of a Korean student. Rhee had not choice but to step down or risk allowing the country to fall into complete chaos. The United States initially welcomed the new democratic government in Seoul, which installed Chang Myŏn as its prime minister. But American officials eventually started to become anxious about Chang’s government. Reluctant to use force, Chang seemed to have trouble maintaining order and Washington was worried that this would open South Korea to invasion or subversion. As a result, when Park Chung Hee seized power in a military coup on May 16, 1961, the United States did little to protest. When the Kennedy administration saw that Park was deeply committed both to maintaining order and promoting rapid economic development it became increasingly supportive, inviting the Major General to Washington in November 1961.

Between 1961 and 1963, when Park governed South Korea through the Supreme Council for National Reconstruction, Washington offered his government continuing economic and military aid but at the same time pressured him to allow free and open elections. Park finally bowed to American pressure in 1963 and managed to capture the presidency in what, according to most accounts, was a reasonably fair election. Once the elections were held and a formal democracy had been created (even if it had some autocratic characteristics) U.S.-South Korean relations improved with many American officials coming to have a great appreciation for Park Chung Hee, who they viewed as one of the few successful modernizers in the postcolonial world. The United States lent Park its political support when he made difficult but unpopular decisions that were necessary for the South Korean economy to take off, such as normalizing relations with Japan, raising interest rates and promoting export led growth.

But relations between the Park government and the United States began to deteriorate with the election of Richard M. Nixon in 1968. Nixon’s determination to reduce American commitments in Asia made Park nervous and convinced him that a stronger, more authoritarian system of government was necessary to combat an increasingly adventurist North Korea. When Park revised the constitution, ended free elections, and declared the creation of Yusin, a harsh new system of authoritarianism in 1972, the Nixon and Ford administrations took a hands-off approach preferring not to interfere in South Korea’s domestic politics. Unfortunately for Park, the policies of Ford’s successor in the White House, Jimmy Carter, were very different. Form the beginning of his presidency, Carter had decided to make human rights an issue and he used it as a platform not only to criticize America’s adversaries but also some of its allies that were governed by conservative dictatorships. Carter’s determination to improve the human rights situation led to a frosty summit in Seoul between the American and South Korean presidents in June 1979. Ultimately, Carter promised to end American troop withdrawals while Park offered vague promises that the human rights situation would improve.

The world will never know if Park truly intended to keep his word. The period after Carter’s visit was one of growing protest against the Yusin system. During a meeting on 26 October, an argument broke out between Park and the director of the Korean Central Intelligence Agency, Kim Chaegyu, over how to handle the turbulent domestic situation. Frustrated, Kim eventually drew his pistol and assassinated Park, ending the president’s nearly twenty-year rule.

The next few months were a complicated period in South Korean politics. The Prime Minister Ch’oe Kyuha assumed the presidency and announced that steps would be taken toward restoring democracy and holding fair elections. At the same time, however, a faction within the military led by General Chun Doo Hwan slowly began taking steps to increase its own control over the ROK’s powerful security apparatus. Americans were initially unsure of how to respond other than hoping that Chun would show restraint and not interfere with civilian control over the government. These hopes were dashed in April, however, when, under duress, President Ch’oe announced that Chun had been promoted to Lieutenant General and appointed as the new director of the KCIA. South Koreans could now read the writing on the wall about the direction their country’s politics was heading in and students began taking to the streets to protest the changes.

The tragic events that followed caused a deep rupture in the relationship between the United States and democratic forces in South Korea. With the demonstrations reaching massive proportions by mid-May 1980, Chun declared martial law, closed all universities and suspended the National Assembly. Protests continued in the southwestern city of Kwangju, however, and Chun sent in paratroopers to suppress the uprisings. Against this background of violent confrontation between the government and protesters, General John Wickham, the commander in chief of American forces in South Korea released the Twentieth Division of the ROK Army from its duties along the DMZ. Chun eventually used this division to violently put down the continuing protests in Kwangju. The fact that Wickham had given his permission for the division to be used caused many South Korean dissidents to see the United States as an oppressive force that supported authoritarianism at the expense of the ROK’s democracy movement.

During the 1980s, America’s approach to Chun Doo Hwan was somewhat conflicted. On the one hand, the Reagan administration continued to offer formal support for Chun’s regime and even made Chun the first guest to visit the Reagan White House in 1981. At the same time, however, Washington put quiet pressure on Chun to make reforms and move toward free elections. But Chun did not move quickly enough and his seven-year rule was marked by constant protests and demands that he step down. Finally, in 1987 a massive wave of protests swept across the entire country. With South Korea tottering on the brink of chaos, Washington finally put strong pressure on Chun to yield and allow free elections. The General finally surrendered to the combination of massive protests and American pressure in June 1987, promising that elections would be held in December.

Since 1987, South Korea has continued to move toward greater democracy and a more open civil society. As this has happened, political relations between the United States and South Korea have generally remained close with Americans frequently praising the ROK as an example of the virtues of democracy. Although the specific policies of the United States toward South Korea and varying personal chemistry between different American and South Korean presidents have at times contributed to tensions between the two governments, the days of Washington trying to control South Korean politics have clearly come to an end. Shared democratic values continue to be an important basis of cooperation between the two governments both in Asia and around the world.

The US-South Korea Military Alliance

The US-ROK military alliance came about most directly as a result of the Korean War. During the war, South Korean forces were put under the operational control of the American led UN Command and following the war control was transferred to US forces that remained stationed in Korea. At the end of the war, the United States and South Korea signed a Mutual Defense Treaty, which became an important cornerstone of the alliance. According to the terms of the treaty, the United States was committed to come to the defense of the Republic of Korea in case of an attack.

The treaty had several important implications. First, the United States gained the right to establish military bases in South Korea and station its troops there. Washington built an extensive system of army, naval, and air bases after the Korean War and initially kept more than 50,000 troops in the ROK. The United States also assumed responsibility for training and supporting South Korean forces. During the 1950s, the Eisenhower administration gave the Syngman Rhee government hundreds of millions of dollars in military aid, supplying as much as 87 percent of the country’s overall defense budget. American largesse enabled Seoul to maintain an army of up to 720,000 troops. Although South Korea was a small country, its army was one of the five largest in the world. The United States also played a critical role in providing training for South Korean forces. Before the Korean War, responsibility for training the ROK military had been given to the Korean Military Advisory Group (KMAG). KMAG continued to function after the war, establishing several training schools and military academies modeled after those in the United States. Moreover, thousands of South Korea’s most promising officers received special training in the United States through a special program for allied forces. The result was that South Korean not only gained an impressive military establishment but that the military began to play an increasingly powerful role in the country’s politics.

The U.S.-South Korean alliance was a critical part of what John Foster Dulles called the “hub and spokes” system of alliances maintained by Washington in East Asia. Rather than establishing a multilateral alliance with its partners in Asia as was done in Western Europe under the auspices of NATO, the United States signed mutual defense treaties through which it created a series of separate bilateral alliances with the ROK, Japan, the Republic of China and the Philippines. This system resulted from a variety of practical concerns. After World War II, a high level of mistrust toward Japan persisted in Asia. Tokyo and Seoul did not even have normal diplomatic relations until 1965, making an Asian version of NATO impossible. Americans also found the system of bilateral alliances useful for keeping the intractable South Korean president, Syngman Rhee, on a tight leash. Rhee had been gravely disappointed that the armistice ending the Korean War had assured the continuing division of the peninsula. Throughout the 1950s he constantly threatened to restart the war and reunify the peninsula by force. As Victor Cha has argue, however, the bilateral alliance system made it much easier for the Eisenhower administration to prevent Rhee from carrying out his plans because it gave Washington a great deal of influence over the ROK military.

During the 1960s, as the threat of North Korean invasion became less pressing, the alliance began to involve into a partnership in which Washington and Seoul cooperated not only on matters directly related to the peninsula but also on issues of regional security. The most important instance of this cooperation was the ROK’s decision to assist American combat efforts in Vietnam through the dispatch of more than 300,000 troops between 1965 and 1973. Partially as a reward to South Korea for its participation in Vietnam, the United States supported a $1.5 billion program to modernize ROK forces between 1971 and 1975. Washington also hoped that this program would enable South Korea to defend itself with a smaller number of American troops in South Korea. As part of the Nixon Doctrine, an effort reduce the American military burden in Asia, the president withdrew the 7th Infantry Division from South Korea, lowering the number of American troops on the peninsula from 60,000 to 40,000.

In recent years, the alliance has become increasingly comprehensive, expanding to include new kinds of threats. By the mid 1980s, the threat of a major war on the Korean peninsula had faded but other concerns became more pressing. North Korea’s nuclear weapons program and the possibilities of proliferation were worrisome to both Washington and Seoul and, while the two have not always been completely in sync on how to manage the threat, they have continued to coordinate strategies for dealing with the DPRK. South Korea has become an important supporter of American counterterrorism efforts. In 2004, it dispatched a contingent of 3,600 troops to Iraqi Kurdistan to assist with peacekeeping and reconstruction. The deployment of a smaller Provincial Reconstruction Team to Afghanistan in 2010 also aided US counterinsurgency efforts in the region. Since the end of the Cold War, the alliance had shown a remarkable capacity to adapt itself to evolving threats and international circumstances. Its ability to do so in the future will be critical to maintaining prosperity and stability in the Pacific.

The US-South Korea Economic Relationship

Like the military alliance, the economic relationship between South Korea and the United States was initially a product of necessity. When American forces occupied southern Korea in 1945, its economic situation was grim as a result of both Japanese imperial policies during the end of World War II and the sudden division of the peninsula. The Korean War only exacerbated these conditions. The war was an incredibly destructive one that did millions of dollars of property damage, destroying roads, schools, hospitals and other institutions that were vital to providing basic necessities. The United States responded through implementing a massive program of economic assistance to South Korea. During the years between 1953 and 1960, South Korea received more economic aid from the United States than did any other county, with annual totals sometimes surpassing $300 million. The money was used to provide food relief, rebuild infrastructure, construct new schools, and train South Korean personnel in administration and other technical fields. Washington also played an important role in creating and funding the United Nations Korea Reconstruction Agency (UNKRA). The organization undertook a number of aid projects in Korea that included providing a team of specialists to train South Korean teachers.

American economic assistance unquestionably played a role in helping South Korea to survive a very difficult period in its history. At the same time, this aid did not stimulate the kind of economic growth that Washington was hoping for. Throughout the 1950s, Americans often looked at South Korea as a basket case; sometimes calling it a “rat hole.” Syngman Rhee’s economic policies were at the heart of the problem. He often diverted American aid to support his political cronies who would in turn provide funding for his regime’s special security forces. Moreover, Rhee was highly obstinate when it came to accepting American economic advice. He refused to normalize relations with Japan—a move that Americans believed was critical to the ROK’s economic future—and insisted on pursuing rapid industrialization rather than the model of export-led development preferred by the United States. The result was that while the South Korean economy managed a modest recovery from the war, it did not thrive.

Souht Korea’s desperate economic situation would begin to change during the 1960s. After Park Chung Hee seized power in a military coup in May 1961, the South Korean government made economic development its top priority. The Kennedy administration changed its policy as well, reducing the overall amount of economic aid given to South Korea while pressuring the ROK government to make adjustments in its economic plans. This led to some clashes over policy issues between Seoul and Washington during Park’s first year in power. The new South Korean leader implemented a currency reform without notifying the United States but the reform failed and drew the ire of American officials. American advisors were also critical of the Five-Year Plan published by the ROK government and forced its revision.

After 1963, however, the Park government and the United States worked closely together to promote South Korea’s economic development. The offices of the ROK Economic Planning Board and the United States Operations Mission in South Korea were located next to each other and American advisors formed close working relationships with the rising generation of Korean economic planners. With American support, Park’s government was able to implement a variety of unpopular but necessary reforms such as improving tax collection and raising interest rates. These reforms created new sources of capital that could be invested in infrastructure. Seoul also followed Washington’s prescriptions to pursue an export led model of development and South Korea’s exports began to increase exponentially by the mid-1960s. The result was that by the late 1960s, South Korea was becoming more self-sufficient and less reliant on American aid to achieve high economic growth rates.

During the 1970s, South Korea became more independent. As its economy continued to achieve double-digit economic growth rates, the United States no longer saw the need for economic aid and such programs were discontinued. The ROK government launched a new initiative known as the “Big Push” that encouraged Korean companies to move into heavy industries such as steel, automobiles, shipping and electronics. The American consumer played an important role in enabling the success of this program as despite the diversification of South Korea’s export markets during this period, the United States and Japan remained the two largest buyers of Korean products.

The United States played a more indirect but still significant role in the process of gradual economic liberalization that occurred in South Korea during the 1980s. Many of the top economic advisors working under President Chun Doo Hwan during this period had received advanced degrees in the United States and were receptive to American guidance on some issues. The Reagan administration constantly pressed the South Korean government to improve the climate for foreign investment. Partially as a result of American pressure, Seoul denationalized its commercial banks and implemented reforms that reduced the state’s role in investment decisions. These policies ultimately made it easier for South Korea to attract foreign investment and helped the ROK to continue to achieve rapid economic growth rates throughout the 1980s and early 1990s.

South Korea’s economy hit a stumbling block as a result of the Asian Financial Crisis in 1997. After speculation caused the currencies of Indonesia and Thailand to collapse during the summer of 1997, the South Korean currency followed suit. While the IMF played the most significant role in arranging a bailout package for the ROK, several American investment banks led by J.P. Morgan helped to reschedule South Korea’s debt, giving it a needed reprieve in its loan payments to foreign banks. By the dawn of the new millennium, South Korea’s economy was growing again and its economic partnerships with the United States continued to stregthen. Recently this partnership has been reaffirmed through the ratification of the KORUS Free Trade Agreement in 2011. The agreement breaks down tariffs and trade barriers and will serve to further increase the volume of trade between the two countries in the twenty-first century.