from Asia Program
from Asia Program

The United States–South Korea Alliance

Why It May Fail and Why It Must Not

Book
Foreign policy analyses written by CFR fellows and published by the trade presses, academic presses, or the Council on Foreign Relations Press.

The alliance between the United States and South Korea has endured through seven decades of shifting regional and geopolitical security contexts. Yet it now faces challenges from within. Domestic political turmoil, including deepening political polarization and rising nationalism in both countries, has cast doubt on the alliance’s viability—with critical implications for the balance of power in East Asia.

Scott A. Snyder provides an authoritative overview of the internal and external pressures on the U.S.–South Korea alliance and explores its future prospects. He argues that nationalist leaders’ accession to power could put past successes at risk and endanger the national security objectives of both countries. In the United States, “America First” nationalism favors self-interest over cooperation and portrays allies as burdens or even free riders. “Korea first” sentiments, in both progressive and conservative forms, present the U.S. military presence in South Korea as an obstacle to Korean reconciliation or a shackle on South Korea’s freedom of action. Snyder also examines North Korea’s attempts to influence South Korean domestic politics and how China’s growing strength has affected the dynamics of the alliance. He considers scenarios in which the U.S.-South Korea relationship weakens or crumbles, emphasizing the consequences for the region and the world. Drawing on this analysis, Snyder offers timely recommendations for stakeholders in both countries on how to preserve and strengthen the alliance.

More on:

South Korea

East Asia

Security Alliances

Timeline: The U.S.-South Korea Alliance, 1950–2023

More on:

South Korea

East Asia

Security Alliances

Reviews and Endorsements

Scott A. Snyder’s book is a bracing reminder that a U.S.–South Korea alliance cannot be taken for granted. Especially timely is Snyder’s detailed discussion of the effect of political polarization, populism, and nationalism in both countries on the future of the alliance. He makes a convincing case for why the alliance continues to matter, more than ever, and how to ensure its vitality going forward.

Kathleen Stephens, former U.S. Ambassador to the Republic of Korea

The U.S.–ROK alliance is back on track under the Biden and Yoon administrations. However, during the Trump and Moon administrations, the alliance became vulnerable. Snyder rightly points out the threats to the alliance from within. This is definitely a must-read book for both practitioners and researchers.

Cheol-Hee Park, chancellor of the Korea National Diplomatic Academy

Snyder is the leading U.S. scholar on the alliance with South Korea. There is much to learn from this book, but the overall theme is particularly compelling: that political polarization at home—on both sides—poses risks to the alliance.

Stephan Haggard, author of Developmental States

In The United States–South Korea Alliance, Snyder once again raises the bar on scholarship covering contemporary Korean affairs. Coinciding with the seventieth anniversary of the alliance, this future-oriented study investigates the domestic political currents and international pressures facing both South Korea and the United States to understand where the alliance is heading and what remains at stake.

Andrew Yeo, author of Asia’s Regional Architecture: Alliances and Institutions in the Pacific Century

Top Stories on CFR

Trade

President Trump doubled almost all aluminum and steel import tariffs, seeking to curb China’s growing dominance in global trade. These six charts show the tariffs’ potential economic effects.

Ukraine

The Sanctioning Russia Act would impose history’s highest tariffs and tank the global economy. Congress needs a better approach, one that strengthens existing sanctions and adds new measures the current bill ignores.

China Strategy Initiative

At the Shangri-La dialogue in Singapore last week, U.S. Secretary of Defense Pete Hegseth said that the United States would be expanding its defense partnership with India. His statement was in line with U.S. policy over the last two decades, which, irrespective of the party in power, has sought to cultivate India as a serious defense partner. The U.S.-India defense partnership has come a long way. Beginning in 2001, the United States and India moved from little defense cooperation or coordination to significant gestures that would lay the foundation of the robust defense partnership that exists today—such as India offering access to its facilities after 9/11 to help the United States launch operations in Afghanistan or the 123 Agreement in 2005 that paved the way for civil nuclear cooperation between the two countries. In the United States, there is bipartisan agreement that a strong defense partnership with India is vital for its Indo-Pacific strategy and containing China. In India, too, there is broad political support for its strategic partnership with the United States given its immense wariness about its fractious border relationship with China. Consequently, the U.S.-India bilateral relationship has heavily emphasized security, with even trade tilting toward defense goods. Despite the massive changes to the relationship in the last few years, and both countries’ desire to develop ever-closer defense ties, differences between the United States and India remain. A significant part of this has to do with the differing norms that underpin the defense interests of each country. The following Council on Foreign Relations (CFR) memos by defense experts in three countries are part of a larger CFR project assessing India’s approach to the international order in different areas, and illustrate India’s positions on important defense issues—military operationalization, cooperation in space, and export controls—and how they differ with respect to the United States and its allies. Sameer Lalwani (Washington, DC) argues that the two countries differ in their thinking about deterrence, and that this is evident in three categories crucial to defense: capability, geography, and interoperability. When it comes to increasing material capabilities, for example, India prioritizes domestic economic development, including developing indigenous capabilities (i.e., its domestic defense-industrial sector). With regard to geography, for example, the United States and its Western allies think of crises, such as Ukraine, in terms of global domino effects; India, in contrast, thinks regionally, and confines itself to the effects on its neighborhood and borders (and, as the recent crisis with Pakistan shows, India continues to face threats on its border, widening the geographic divergence with the United States). And India’s commitment to strategic autonomy means the two countries remain far apart on the kind of interoperability required by modern military operations. Yet there is also reason for optimism about the relationship as those differences are largely surmountable. Dimitrios Stroikos (London) argues that India’s space policy has shifted from prioritizing socioeconomic development to pursuing both national security and prestige. While it is party to all five UN space treaties that govern outer space and converges with the United States on many issues in the civil, commercial, and military domains of space, India is careful with regard to some norms. It favors, for example, bilateral initiatives over multilateral, and the inclusion of Global South countries in institutions that it believes to be dominated by the West. Konark Bhandari (New Delhi) argues that India’s stance on export controls is evolving. It has signed three of the four major international export control regimes, but it has to consistently contend with the cost of complying, particularly as the United States is increasingly and unilaterally imposing export control measures both inside and outside of those regimes. When it comes to export controls, India prefers trade agreements with select nations, prizes its strategic autonomy (which includes relations with Russia and China through institutions such as the Shanghai Cooperation Organization and the BRICS), and prioritizes its domestic development. Furthermore, given President Donald Trump’s focus on bilateral trade, the two countries’ differences will need to be worked out if future tech cooperation is to be realized.