Updated July 21, 2022
South Korea: Background and U.S. Relations
Overview
Korea in 2022 to conduct its 7th nuclear weapons test, and
South Korea (officially the Republic of Korea, or ROK) is
first since September 2017. (In 2018, Kim had also
one of the United States’ most important strategic and
announced a moratorium on further nuclear tests.) North
economic partners in Asia. The U.S.-ROK Mutual Defense
Korea also conducts cyberattacks around the globe.
Treaty, signed in 1953 at the end of the Korean War,
Whereas the previous Moon government had emphasized
commits the United States to help South Korea defend
diplomacy with North Korea, Yoon and Biden have
itself, particularly from North Korea (officially the
Democratic People’s Republic of Korea, or DPRK
emphasized deterrence. They reactivated a high-level
). The
consultation group on extended deterrence under the U.S.
alliance also helps the United States to promote its interests
nuclear umbrella and announced their intent to expand the
in East Asia and around the globe, including through South
scope and scale of combined military exercises. Trump and
Korean contributions of troops to U.S.-led military
Moon had curtailed the exercises since June 2018. At the
operations. Approximately 28,500 U.S. troops are based in
May 2022 Biden-Yoon summit, the United States also
the ROK. The economic relationship is bolstered by the
committed to deploy strategic assets such as stealth fighter
U.S.-South Korea Free Trade Agreement (KORUS FTA),
jets in a “timely and coordinated manner as necessary.” In
implemented in 2012. In 2021, South Korea was the United
States’ seventh
June, the allies staged combined military exercises that
-largest trading partner (goods and services
included a U.S. aircraft carrier for the first time in over four
trade combined), and the United States was South Korea’s
years.
second-largest trading partner, behind China.
The Biden Administration has stated it is pursuing a
In March 2022, South Koreans narrowly elected former
“calibrated, practical approach that is open to and will
chief prosecutor Yoon Suk-yeol as their next president.
explore diplomacy with North Korea” while retaining U.S.
Yoon, who represents the conservative People Power Party
and international sanctions to achieve the eventual
(PPP), succeeded president Moon Jae-in from the
“complete denuclearization of the Korean Peninsula.” This
progressive Minjoo (Democratic) Party. Yoon says he
wants to transform South Korea into a “global pivotal state”
appears to envision incrementally offering partial sanctions
relief in exchange for partial steps toward denuclearization.
by raising its profile beyond the Korean Peninsula, by
playing a larger role in regional groupings, and by
becoming a more active partner in the United States’ Indo-
Pacific strategy. Ten days after Yoon’s May 2022
inauguration, President Biden visited South Korea. In
addition to discussing ways to cooperate on North Korea
policy, Biden and Yoon broadened the aperture of bilateral
cooperation around the globe, announcing steps to deepen
cooperation on pandemic prevention, space, and climate
change. They also took steps to integrate South Korean
companies more fully into U.S. efforts to promote
technological development and supply chain resiliency.
South Korea became one of 14 inaugural negotiating
partners in the U.S.-led Indo-Pacific Economic Framework
for Prosperity (IPEF) initiative, a proposed new trade and
economic arrangement.
North Korea Policy Coordination
North Korea is the dominant strategic concern in the U.S.-
South Korea relationship. Following the collapse of former
President Trump’s diplomatic efforts with North Korean
leader Kim Jong-un in 2019, Pyongyang largely has
U.S.-South Korea Security Issues
ignored U.S. and South Korean outreach, including
The Biden Administration has worked to repair the alliance.
humanitarian aid offers, and has severed all overt inter-
It had been strained during the Trump years, prompting
Korean communication channels for extended periods.
Congress to impose conditions (via the National Defense
Since the start of 2022, North Korea has conducted over 20
Authorization Act) on Trump’s power to withdraw U.S.
missile tests, including multiple tests of intercontinental
troops from South Korea. In February 2021, the Biden
ballistic missiles (ICBMs), which are capable of delivering
Administration concluded a cost-sharing negotiation with
nuclear warheads. These ICBM test-launches, North
South Korea that boosted South Korea’s contribution to
Korea’s first since November 2017, ended Kim’s self-
alliance costs by 13.9%. The ROK traditionally has paid for
declared ICBM test moratorium. Analysts expect North
about 50% (over $800 million annually) of the total non-
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South Korea: Background and U.S. Relations
personnel costs of the U.S. military presence, according to
and Seoul have taken incremental steps to reverse this trend
congressional testimony by U.S. military officials.
by attending multiple high-level trilateral and bilateral
meetings, but it is unclear how they will resolve the
Washington and Seoul have been adapting the alliance to
thorniest historical issues in order to deepen trust.
recognize South Korea’s increased capabilities and desire
for greater autonomy. For over a decade, they have been
U.S.-South Korea Economic Relations
preparing to transfer wartime operational control (OPCON)
U.S. goods and services exports to South Korea totaled
to a binational command led by an ROK general with a
$86.1 billion in 2021, and imports totaled $108.4 billion.
U.S. deputy. Under the existing arrangement, South Korean
Autos and parts accounted for one-quarter of U.S. imports
soldiers would be under a binational command led by a
($27.1 billion). In 2020, the stock of South Korean FDI in
U.S. general in the event of war. The two sides have
the United States was $63.7 billion, and U.S. FDI to South
established conditions and benchmarks to demonstrate that
Korea was $33.9 billion. South Korean FDI has grown
the ROK can assume wartime OPCON, including improved
significantly and nearly 100,000 workers in the United
ROK capabilities to lead combined forces and counter the
States were employed by South Korean multinational firms
DPRK nuclear and missile threat, and a security
in 2019. Since early 2021, South Korean companies have
environment on the Peninsula conducive to a transfer.
announced pledges of $25 billion in new U.S. investment
Additionally, U.S. forces in the ROK have consolidated
with a focus on cooperation in key technologies including
their presence, in part to return land to South Korea. South
electric vehicle batteries, semiconductors, and artificial
Korea has paid $9.7 billion—about 94% of total costs—to
intelligence.
construct new facilities such as the recently opened Camp
The KORUS FTA has been the centerpiece of U.S.-South
Humphreys, the largest overseas U.S. base. Another
Korea trade and investment relations since its entry into
example of alliance adaptation is a May 2021 decision to
force in 2012. Most U.S. business groups support the
terminate the bilateral Missile Guidelines agreement,
agreement, highlighting market access improvements in
originally signed in 1979, which limited the range of South
South Korea and a more robust mechanism for dispute
Korean ballistic missiles to 800 km (497 miles).
resolution, though the two countries continue to engage on
Reaction to Russia’s Invasion of Ukraine
implementation issues. The Trump Administration
Following Russia’s February 2022 invasion of Ukraine,
negotiated limited modifications to the KORUS FTA,
South Korea imposed sanctions against Russia and has
which took effect in 2019 and included a delay until 2041
offered $100 million in humanitarian aid and non-lethal
in reductions to U.S. light truck tariffs. South Korea’s
equipment to Ukraine. The Yoon government reportedly
participation in the IPEF initiative may provide an
has begun discussions on selling arms to countries such as
opportunity to further enhance economic ties, including on
Poland and Canada to help them replace equipment sent to
digital trade issues, a priority area for both countries.
assist Ukraine. Yoon also joined a June 2022 NATO
Bilateral trade frictions have been less pronounced under
summit in Madrid, a first for a South Korean leader. South
President Biden than under the Trump Administration.
Korea did not impose sanctions on Russia following its
However, Trump-era import restrictions on South Korean
2014 invasion of Crimea.
products, including steel, aluminum, washing machines,
South Korea’s Regional Relations
and solar products, remain in effect.
Because of both North Korea and South Korea’s economic
South Korean Politics
dependence on China, Seoul calibrates its North Korea
Yoon, a political newcomer who won by a margin of less
policy with an eye on China-DPRK relations. China is
than 1% of the vote, will have to contend with a National
South Korea’s largest trading partner and second-largest
Assembly firmly controlled by the opposition Minjoo Party.
destination for foreign direct investment (FDI). In the past,
(See Figure 1.) Divided government is likely to complicate
Beijing has imposed retaliatory economic measures on
Yoon’s ability to secure major achievements in areas that
South Korean companies for Seoul’s policy choices. Moon
require new legislation, such as in domestic policy.
and Yoon signed on to language expressing concern about
stability in the Taiwan Strait in joint statements with
Figure 1. South Korea’s National Assembly
President Biden, and public opinion in South Korea also has
turned more negative toward China. Yoon has indicated
interest in participating in the vaccine, climate change, and
emerging technology working groups established by the
Quadrilateral Security Dialogue—also known as “the
Quad”—among Australia, India, Japan, and the United
States, despite China’s criticism of the Quad.
Source: National Assembly website, accessed June 4, 2022.
ROK-Japan relations are perennially fraught because of
sensitive legacy issues from Japan’s colonization of the
Mark E. Manyin, Specialist in Asian Affairs
Korean Peninsula from 1910 to 1945. Since 2018, a series
of actions and retaliatory countermeasures by both
Emma Chanlett-Avery, Specialist in Asian Affairs
governments involving trade, security, and history-related
Brock R. Williams, Specialist in International Trade and
controversies caused South Korea-Japan relations to
Finance
plummet, eroding U.S.-ROK-Japan policy coordination.
IF10165
With encouragement from the Biden Administration, Tokyo
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South Korea: Background and U.S. Relations
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https://crsreports.congress.gov | IF10165 · VERSION 32 · UPDATED