Diplomatic relations between South Korea and the United States commenced in 1949. The United States helped establish the modern state of South Korea, officially the Republic of Korea, and fought on its UN-sponsored side in the Korean War (1950–1953). During the subsequent decades, South Korea experienced tremendous economic, political and military growth. To date, the United States recognized the ROK as the sole legitimate government of Korea.
South Korea has a long military alliance with the United States, aiding the U.S. in every war since the Vietnam War, including the Iraq War. At the 2009 G20 London summit, then-U.S. president Barack Obama called South Korea "one of America's closest allies and greatest friends". In 1987, South Korea was among the first batch of countries to be designated as a major non-NATO ally. In June 2023, South Korean president Yoon Suk Yeol said that he had upgraded the country's alliance with the United States to one that is "nuclear-based" in the face of North Korea's growing military threat.
According to a 2026 Pew Research poll, 45% of South Koreans had a favorable view of the United States, while 55% had a negative view. According to a 2018 Gallup poll, 77% of Americans had a favorable view of South Koreans, while 22% had a negative view.
Contents
Country comparison
Leaders of South Korea and the United States from 1950
History
Background
Following the United States expedition to Korea in 1871, the United States and Joseon established diplomatic relations under the 1882 Treaty of Peace, Amity, Commerce, and Navigation. In 1883, Joseon sent the first ever Korean special mission to the United States, also known in Korean as Bobingsa (보빙사; 報聘使). However, Japan assumed direction over Korean foreign affairs in 1905 and in 1910 began a 35-year period of colonial rule over Korea.
In 1945, Japan surrendered to the Allies at the end of World War II. The United States proposed to the USSR that they could share responsibility of the Korean peninsula, dividing the Korean peninsula at the 38th parallel into two occupation zones, with the United States in the South and the Soviet Union in the North. This was intended to be a temporary measure.
Each half was polarized politically: the USSR-backed North was led by the Communist Party, while U.S. General John Hodge handpicked far-right Syngman Rhee to lead the South. Initial talks in 1945–6 to achieve a unified, independent Korea were not successful. The U.S. petitioned the United Nations to find a resolution, and the UN concluded that elections should be held. In reality, only the South held an election, as the North refused to allow UN officials entry to supervise the election. Syngman Rhee was officially elected after ruling the South for several years already, and in turn Stalin's regime appointed Communist Kim Il-Sung without an election.
In 1948, two separate nations were established: the Republic of Korea (ROK) in the South, and the Democratic People's Republic of Korea (DPRK) in the North. On January 1, 1949, the United States officially recognized the Republic of Korea as the sole legitimate government of Korea and established diplomatic relations on March 25 of that year.
Korean War 1950-1953
Cross-border skirmishes and raids at the 38th Parallel escalated into open warfare when the North Korean forces started to invade South Korea on June 25, 1950. In response, 16 member countries of the United Nations, led by the United States, came to the defense of South Korea. It was the first significant armed conflict of the Cold War with extensive deployment of U.S. and other troops. The Korean War was a major Cold War military clash fought up and down the peninsula of Korea, finally leading to a stalemate in 1953 that restored the boundaries to nearly what they were at the start, along the 38th parallel. The war was initiated by Kim Il-sung of the Democratic People's Republic of Korea (North Korea), with assistance from China and the Soviet Union[1] were arrayed against the Republic of Korea (South Korea), supported by the United States of America and a multinational United Nations force.
The war began with an invasion by North Korea in June 1950, followed by an unexpected American entry. North Korean forces had pushed the South Koreans and Americans back into a small perimeter around the port of Pusan. In September 1950, an amphibious landing at Inchon, followed by a breakout from the Pusan Perimeter, turned the tide. The North Korean People's Army (NKPA) disintegrated as the allies moved north, with UN approval, to unify the country. Unexpectedly the Chinese then sent in large numbers of infantry, and in the bitter cold of November-January 1950-51 pushed the UN forces out of the north. Communist supply lines were fragile, especially in the face of heavy American bombing, so the lines stabilized close to the 38th parallel in 1951. Two more years of static warfare followed, with the issue of returning reluctant Communist prisoners of war held by the UN the major sticking point. Finally an armistice was reached in summer 1953; the prisoners were exchanged and fighting ended in an uneasy truce that continues into the 21st century.
The war was limited in size and scope, but casualties were heavy on both sides. In the U.S., the political consequences of the war contributed to the defeat of the Truman administration and his Democratic party in the 1952 election of General Dwight D. Eisenhower, the Republican candidate who promised to end the war. For Americans and Chinese it is a "forgotten war", neglected on the timeline between the twin cataclysms of World War II and Vietnam. For the Koreans it is the central event of their modern history, and efforts to reunify the land continue.
Origins of the South Korea–United States alliance
In 1953, following the end of the Korean War, the United States established a bilaterial alliance pact with South Korea.
Moreover, the "U.S. alliance with South Korea would consequently have three functions. First, it would serve as part of a network of alliances and military installations designed to ring the Soviet threat in the Pacific. Second, it would deter a second North Korean attack, with U.S. ground troops serving as the 'tripwire' guaranteeing U.S. involvement. Third, it would restrain the South from engaging in adventurism".
The United States and South Korea are allies under the 1953 Mutual Defense Treaty. Under the agreement, U.S. military personnel have maintained a continuous presence on the Korean peninsula.
Issues and recent history
In 1953, at the end of the Korean War, the number of prostitutes in South Korea was estimated as about 350,000, with about 60 percent working near U.S. military camps. In the post-Korean War period, the U.S. military continued to contribute significantly to the South Korean economy, providing an estimated 1 percent of the South Korean GNP in 1991, including the sex industry. Despite the world-wide growth of women's human rights advocacy since the 1990s, and the shift towards foreign workers providing sex services for U.S. troops, (particularly women trafficked from the Philippines and the former Soviet Union), prostitution via "juicy bars" remains an issue near U.S. bases in South Korea.
In 1992, Yun Geum-i, a 26-year-old woman, was brutally killed by a U.S. serviceman, Private Kenneth L. Markle, in Dongducheon. In August 1993, the U.S. government compensated the victim's family with a payment of about US$72,000. Markle was sentenced by a South Korean court to life imprisonment, later reduced to 15 years. Professor Katharine Moon notes that the murder was not unique, and did not spark a national debate about the presence of U.S. forces. However, it did become a "call to action" for some Koreans, and led to the establishment of the "National Campaign for the Eradication of Crimes by U.S. troops."
In July 2000, the Eighth U.S. Army apologized for an incident where formaldehyde, a toxic fluid, was released into the Han River in February of that year. In a report released in 2017 detailing spill incidents from 1995 to 2015 at the US garrison in Yongsan, South Korean environmentalist groups expressed concern about the lack of transparency and the possibility of continued water contamination, as well as who would take responsibility for cleanup of the site.
On 13 June 2002, two 14-year-old South Korean schoolgirls were crushed to death by a 50-ton United States Army vehicle in Yangju. Anti-Americanism was pervasive after the driver and the navigator of the vehicle were both acquitted in U.S. courts-martial on charges of negligent homicide. There was resentment from protesters towards the U.S.–South Korea Status of Forces Agreement, which restricted South Korea from having jurisdiction over alleged crimes that occurred when American soldiers were on official duty. South Korean presidential candidate Lee Hoi-chang called on United States President George W. Bush to "apologize to soothe the pain of the Korean people and to prevent any escalation in anti-American sentiment". American ambassador to South Korea Thomas C. Hubbard apologized on behalf of Bush.
The United States military in Korea
South Korea and the United States agreed to a military alliance in 1953. They called it "the relationship forged in blood". In addition, roughly 29,000 United States Forces Korea troops are stationed in South Korea. In 2009, South Korea and the United States pledged to develop the alliance's vision for future defense cooperation. Currently, South Korean forces would fall under United States control should the war resume. As of September 2023, the transfer of this war time control to South Korea is on an indefinite “conditions-based” timeline. Proposals to modernize the alliance include increasing South Korea’s defense budget to 3.5–3.8% of GDP, enhancing cost-sharing for U.S. Forces Korea, and maintaining a clear transfer plan for wartime operational control while ensuring continued U.S. military presence and extended nuclear deterrence.
At the request of the United States, President Park Chung Hee sent troops to Vietnam to assist American troops during the Vietnam War, maintaining the second largest contingent of foreign troops after the United States. In exchange, the United States increased military and economic assistance to South Korea. In 2004, President Roh Moo-hyun authorized dispatching a small contingent of troops to Iraq at the request of U.S. President George W. Bush.
Since 2009, air forces of South Korea and the U.S.A. have conducted annual joint exercises under the name "Max Thunder". In 2018, the drills began on May 11 and continued until May 17.
At a Cabinet meeting in Seoul on 10 July 2018, the government decided not to hold that year's Ulchi drill, scheduled for June 2018. The Government said the decision was made in line with recent political and security improvements on the peninsula and the suspension of South Korea-U.S. joint military exercises.
Former South Korean President Moon Jae-in, elected in May 2017, has said he supports the continuation of sanctions against North Korea if it is aimed at bringing North Korea out of its state of isolation and to the negotiating table. He also argued, at the same time, that he was against a "sanctions-only" approach toward North Korea. His approach to North Korea is similar to Kim Dae-jung's Sunshine Policy, which only continued up to the Roh Mu-hyun's administration.
Nuclear and missile diplomacy
Between 1958 and 1991, the United States based a variety of nuclear weapons in South Korea. The number reached a peak of 950 warheads in 1967. Since 1991, when President George H. W. Bush announced the withdrawal of all tactical nuclear weapons based abroad, the Korean peninsula has seen ongoing efforts by the U.S. to negotiate an end to North Korea's own nuclear and missile development. These efforts have been characterized by "stalemates, crises and tentative progress." Despite the ongoing tensions, the U.S. has not redeployed nuclear weapons, although one recent press report suggests a majority of South Koreans are in favor of developing their own nuclear weapons. South Korea announced the deployment of the Terminal High Altitude Area Defense anti-ballistic missile defense system at the end of 2017.
Opinion polls
According to Pew Research Center in 2026, 45% of South Koreans have a favorable view towards the United States, while 55% have an unfavorable opinion. On the political side, the United States supported South Korea after 1945 as a "staunch bastion against communism", even when the ROK itself was ruled by a US-backed dictatorship. According to Pew Research Center in 2026, 77% of South Koreans have little or no confidence on U.S. President Donald Trump, while 22% have some or a lot of confidence. In 2025, a poll by the Korea Institute for National Unification showed that 65.7% of South Koreans agreed that the United States "does not consider South Korea’s interests". According to a KStatResearch poll in October 2025, 56% of South Koreans had favorable opinions of the United States, while 40% had a negative opinion; most commonly cited reasons for negative opinions were Trump administration's erratic policies (46%), economic burden imposed by the US (26%), and the America First policy (20%). Additionally, only 27% of respondents said that "some national interests should be sacrificed" for the sake of the alliance with the United States, while 68% responded that "national interests should be the top priority".
As relations with Korea waxed hot and cold under President Donald Trump, American public opinion regarding North Korea likewise fluctuated sharply, and no clear picture emerges.
Economic relations
US companies were actively involved in the development of the South Korean automotive industry. After Hyundai entered the automobile business in 1967, Ford provided technical assistance. A joint venture between General Motors and Shinjin Motor Company began car production in 1972.
In the 1980s, there were dozens of agreements in which US semiconductor companies sold or licensed chip technology to South Korean companies. The transfers occurred amidst the dominance of Japanese companies and a slump in the industry.
In 2011, President Lee Myung-bak signed the United States–Korea Free Trade Agreement.
US policy under Joe Biden such as the 2022 Inflation Reduction Act (IRA) and CHIPS and Science Act attracted South Korean businesses in industries such as electric vehicles, batteries, semiconductors, and solar panels to build production facilities in the US. These investments were mainly in southern states. Although the IRA initially created discord in relations, the US government accommodated South Korean corporate interests. Donald Trump, however, revoked most Biden-era tax credits in the One Big Beautiful Bill Act, replacing them with tariffs. Various joint ventures between US automakers and South Korean battery makers were consequently dissolved. In September 2025, the US government detained hundreds of South Korean nationals in a raid of a Hyundai-LG battery plant in Georgia state. A poll found that a majority of South Koreans surveyed found the crackdown to be excessive.
The South Korean government's response to Coupang's 2025 data breach created tension with the US government.
South Korea's export-driven economy and competition with domestic U.S. producers in certain fields of products have led to some trade friction with the United States. For example, imports of certain steel and non-steel products have been subject to U.S. anti-dumping and countervailing duty investigations. A total of 29 U.S. imports from South Korea have been assessed. There have also been major trade disputes between South Korea and the U.S. in areas such as telecommunications, automotive industry, intellectual property rights issues, pharmaceutical industry, and the agricultural industry.
Trade volume
South Korea Exports to United States was US$110.17 Billion during 2022, according to the United Nations COMTRADE database on international trade. In 2022, South Korea mainly exported Vehicles other than railway and tramway to the United States.
Direct investment
The U.S. (US$8.73 billion) is one of the top destinations for Korean FDI.
Space cooperation
The two countries are deepening space cooperation by signing a bilateral space agreement in 2016. In April 2023, President Yoon visited the Goddard Space Flight Center with U.S. Vice President Kamala Harris, and agreed to work to strengthen the space alliance between South Korea and the United States. In July 2024, Pamela Melroy, Deputy Administrator of the NASA, visited South Korea to discuss space cooperation.
Cultural exchange
The South Korean government maintains Korean cultural education centers in Wheeling, Illinois (in the northwest suburbs of Chicago), Houston, New York City, Los Angeles, San Francisco, and Washington, D.C.
South Korea has a total of three Korean Cultural Centers in the United States.
Korean Cultural Center, Los Angeles
Korean Cultural Center New York
Korean Cultural Center Washington D.C.
K-pop
K-pop and Korean cultural festivals are held in the U.S. regularly across different regions. KCON, the world's largest Hallyu (Korean Wave) festival (organized by CJ ENM), surpassed 1.5 million cumulative on-site visitors by the 18th edition. The achievement came 11 years after its first event in Irvine, California in 2012 and just 4 years after it reached the milestone of 1 million attendees in 2019.
As of 2023, The U.S. is one of the top three countries for K-pop albums.
Korean language education
Korean language is one of the only three in the U.S. university foreign language enrollment rate to rise from 2016 to 2021. The number of Korean language learners increased from 13,900 in 2016 to 19,300 in 2021.