How fear of entrapment shapes South Korean public opinion on conflicts with North Korea under US extended deterrence

ABSTRACT

The nuclear crises in 1994 and 2017 between the United States and North Korea introduced South Korea to the fear of becoming entrapped in unwanted wars on the Korean Peninsula. To understand how the fear of entrapment shapes a client state’s strategic judgments toward the use of force by a patron state under extended deterrence, we designed novel experiments on pre- and post-strike approval of military operations by combining war-game scenarios and survey experiments. In the pre-strike-approval experiment, we examined how the decision-making mechanism for military planning and operations, the type of weapon systems, and the expected casualties shape South Korean public opinion on the use of US military strikes against North Korea. In the post-strike-approval experiment, we provided South Koreans with outcomes of military strikes and examined how US unilateral military strikes against North Korea would change public attitudes toward the US–South Korea alliance. We found that the fear of US unilateral use of force and consequent entrapment in unwanted wars substantially decreased South Korean public approval of the military strikes against North Korea. We also found that US unilateral military strikes against North Korea, regardless of their success or failure, would severely harm the US–South Korea alliance.

KEYWORDS:

• extended deterrence
• security commitment
• nuclear weapons
• alliance
• foreign policy
• public opinion
• North Korea

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 White House, “Washington Declaration,” April 26, 2023, <https://www.whitehouse.gov/briefing-room/statements-releases/2023/04/26/washington-declaration-2/>.

2 For a discussion of the debate over nuclear-weapons acquisition in South Korea, see Jiyoung Ko, “Alliance and Public Preference for Nuclear Forbearance: Evidence from South Korea,” Foreign Policy Analysis, Vol. 15, No. 4 (2019), pp. 509–29; Sangyong Son and Man-Sung Yim, “Correlates of South Korean Public Opinion on Nuclear Proliferation,” Asian Survey, Vol. 61, No. 4 (2021), pp. 1–30; Sangyong Son and Jong Hee Park, “Nonproliferation Information and Attitude Change: Evidence from South Korea,” Journal of Conflict Resolution, Vol. 67, No. 6 (2022), pp. 1095–127.

3 Here we are using the original definition of “entrapment,” from Glenn Snyder: “being dragged into a conflict over an ally’s interests that one does not share, or shares only partially.” Glenn Snyder, “The Security Dilemma in Alliance Politics,” World Politics, Vol. 36, No. 4 (1984), p. 467.

4 For example, South Korean President Kim Yong-Sam shared his strong opposition to the Clinton administration’s actions and warned that South Korea would not mobilize any military forces for US unilateral military operation against North Korea, out of fear of escalation to full-fledged war on the Korean Peninsula. See Jongsik Ahn, “다시보는 1994년 북폭위기 … 미국은 독자 북폭할 수 있나” [Revisiting the 1994 nuclear crisis … Could the United States have launched unilateral military strikes on North Korea?], SBS News, April 11, 2017, <https://news.sbs.co.kr/news/endPage.do?news_id=N1004140436>. All translations in this article of article titles, survey scenarios, and other material are by the authors.

5 Michael Mandelbaum, The Nuclear Revolution (Cambridge, UK: Cambridge University Press, 1981); Glenn Snyder, Alliance Politics (Ithaca, NY: Cornell University Press, 2007).

6 Tongfi Kim, “Why Alliances Entangle but Seldom Entrap States,” Security Studies, Vol. 20, No. 3 (2011), pp. 350–77; Alexander Lanoszka, “Tangled Up in Rose? Theories of Alliance Entrapment and the 2008 Russo-Georgian War,” Contemporary Security Policy, Vol. 39, No. 2 (2018), pp. 234–57. But see also Lauren Sukin’s explanation of how the fear of entrapment increases public support for nuclear-weapons development in a client state. Lauren Sukin, “Credible Nuclear Security Commitments Can Backfire: Explaining Domestic Support for Nuclear Weapons Acquisition in South Korea,” Journal of Conflict Resolution, Vol. 64, No. 6 (2019), pp. 1011–42.

7 Hwan Kang, “Korea Passing: Seoul’s New Foreign Policy Concern,” Korea Economic Institute, September 26, 2017, <https://keia.org/the-peninsula/korea-passing-seouls-new-foreign-policy-concern/>; John Lyons, “In the North Korea Standoff, South Koreans Say, ‘What About Us?’” Wall Street Journal, August 30, 2017,<https://www.wsj.com/articles/south-koreans-feel-overlooked-by-u-s-in-north-korea-debate-1504109030>.

8 Seungjun Lee, “대선후보들, 미 대북 선제타격 ‘무조건 막아야’ 한목소리” [South Korean presidential candidates have spoken to prevent US preventive strikes against North Korea], The Hankyoreh, April 13, 2017, <https://www.hani.co.kr/arti/politics/assembly/790530.html>.

9 Geon-taek Kang, “홍준표 文정권 들어서면 트럼프가 상의없이 北선제타격” [Hong Joon-pyo says if Moon Jae-in is elected, President Trump will launch a preventive strike against North Korea without consulting South Korea], Yonhap News, April 8, <https://www.yna.co.kr/view/AKR20170408027351001>.

10 Sang-Hun Choe, “South Korea’s Leader Bluntly Warns U.S. against Striking North,” New York Times, August 15, 2017, <https://www.nytimes.com/2017/08/15/world/asia/south-korea-moon-jae-in-trump.html>.

11 Victor Cha, “Abandonment, Entrapment, and Neoclassical Realism in Asia: The United States, Japan, and Korea,” International Studies Quarterly, Vol. 44, No. 2 (2000), pp. 261–91.

12 Preemptive strikes and preventive strikes have much in common, but they are distinct concepts. Preemptive strikes are launched when an enemy attack is imminent, and striking first has more advantages than being attacked. In contrast, preventive strikes are launched in response to less immediate threats where an enemy’s attack is not imminent but the delay would involve greater risks in the future.

13 Keir Lieber and Daryl Press, “The New Era of Counterforce: Technological Change and the Future of Nuclear Deterrence,” International Security, Vol. 41, No. 4 (2017), pp. 9–49; Paul Davis and Bruce Bennett, “Nuclear-Use Cases for Contemplating Crisis and Conflict on the Korean Peninsula,” Journal of Peace and Nuclear Disarmament, Vol. 5, No. S1 (2022), pp. 24–49; Anastasia Barannikova, “Korean Peninsula Nuclear Issue: Challenges and Prospects,” Journal of Peace and Nuclear Disarmament, Vol. 5, No. S1 (2022), pp. 50–68; Sangkyu Lee, “Prospects for DPRK’s Nuclear Use Scenarios and Deterrence Measures of the US and ROK Alliance,” Journal of Peace and Nuclear Disarmament, Vol. 5, No. S1 (2022), pp. 69–84.

14 Alida R. Haworth, Scott D. Sagan, and Benjamin A. Valentino, “What Do Americans Really Think about Conflict with Nuclear North Korea? The Answer Is Both Reassuring and Disturbing,” Bulletin of the Atomic Scientists, Vol. 75, No. 4 (2019), pp. 179–86.

15 But see David Allison, Stephen Herzog, and Jiyoung Ko, “Under the Umbrella: Nuclear Crises, Extended Deterrence, and Public Opinion,” Journal of Conflict Resolution, Vol. 66, No. 10 (2022), pp. 1766–96.

16 Adam Berinsky, In Time of War: Understanding American Public Opinion from World War II to Iraq (Chicago: University of Chicago Press, 2009); Christopher Gelpi, Peter Feaver, and Jason Reifler, Paying the Human Costs of War (Princeton, NJ: Princeton University Press, 2009); Richard Eichenberg, “Victory Has Many Friends: US Public Opinion and the Use of Military Force,” International Security, Vol. 30, No. 1 (2005), pp. 140–77.

17 Philip Powlick and Andrew Katz, “Defining the American Public Opinion/Foreign Policy Nexus,” Mershon International Studies Review, Vol. 42, No. S1 (1998), pp. 29–61.

18 Matthew Baum and Tim Groeling, “Reality Asserts Itself: Public Opinion on Iraq and the Elasticity of Reality,” International Organization, Vol. 64, No. 3 (2010), pp. 443–79; Douglas Foyle, Counting the Public in: Presidents, Public Opinion, and Foreign Policy (New York: Columbia University Press, 1999).

19 See the Appendix for more information on sample characteristics.

20 To provide survey participants with more realistic information, we conducted semi-structured interviews with government officials and nuclear scientists who had relevant policy experience and expertise.

21 See the Appendix for the survey script.

22 The difference in military effectiveness between conventional and nuclear weapons reflects the hardened and deeply buried underground military targets in North Korea. Although conventional missiles are a more viable option, low-yield nuclear weapons, with their earth-penetrating capabilities, are more effective than conventional weapons in destroying deep underground facilities.

23 See the Appendix for statistics (such as mean, standard deviation, and confidence interval) used for drawing interval plots.

24 Son and Park, “Nonproliferation Information and Attitude Change.”

25 On average, 77.5 percent of survey participants answered that the United States was a credible ally under the US–South Korean-joint-military-strike condition; only 34 percent answered that the United States was a credible ally under the US-unilateral-military-strike scenario.

26 In the presidential election in March 2022, Yoon defeated Lee by less than one percentage point.

27 Haworth et al., “What Do Americans Really Think,” pp. 179–86.

28 Daryl Press, Scott Sagan, and Benjamin Valentino, “Atomic Aversion: Experimental Evidence on Taboos, Traditions, and the Non-use of Nuclear Weapons,” American Political Science Review, Vol. 107, No. 1 (2013), pp. 188–206; Lisa Koch and Matthew Wells, “Still Taboo? Citizens’ Attitudes toward the Use of Nuclear Weapons,” Journal of Global Security Studies, Vol. 6, No. 3 (2021), <https://doi.org/10.1093/jogss/ogaa024>; Tyler Bowen, Michael Goldfien, and Matthew Graham, “Public Opinion and Nuclear Use: Evidence from Factorial Experiments,” Journal of Politics, Vol. 85, No. 1 (2023), pp. 345–50.

29 Brian Rathbun and Rachel Stein, “Greater Goods: Morality and Attitudes toward the Use of Nuclear Weapons,” Journal of Conflict Resolution, Vol. 64, No. 5 (2020), pp. 787–816; Michal Smetana and Marek Vranka, “How Moral Foundations Shape Public Approval of Nuclear, Chemical, and Conventional Strikes: New Evidence from Experimental Surveys,” International Interactions, Vol. 45, No. 2 (2021), pp. 374–90.

30 Charli Carpenter and Alexander Montgomery, “The Stopping Power of Norms: Saturation Bombing, Civilian Immunity, and US Attitudes toward the Laws of War,” International Security, Vol. 45, No. 2 (2020), pp. 140–69.

31 Michael Doyle, Ways of War and Peace (New York: W.W. Norton, 1997); Bruce Russett and John Oneal, Triangulating Peace: Democracy, Interdependence and International Organizations (New York: W.W. Norton, 2001).

1 Please refer to <https://embrain.com/eng/>.

Additional information

Notes on contributors

Sangyong Son

Sangyong Son is a PhD candidate in the Department of Politics at New York University. His research focuses on nuclear weapons and political violence, with a regional focus on East Asia.

Hyeongpil Ham

Hyeongpil Ham, an army colonel, received his PhD in nuclear science and engineering from the Massachusetts Institute of Technology. He has worked for more than 30 years for South Korea’s Ministry of National Defense, Korea Arms Verification Agency, Korea Institute of Defense Analyses, and Ministry of Foreign Affairs. He worked to strengthen the implementation of the US–South Korea alliance’s Tailored Deterrence Strategy against North Korea’s nuclear and missile threat while serving as director of the Nuclear Policy Division at the Ministry of National Defense and as chair of the working-level meetings of the ROK–US Deterrence Strategy Committee. He also led the military task force responsible for developing South Korea’s deterrence and defense strategy and providing advice on complete denuclearization of the Korean Peninsula to the Ministry of Foreign Affairs and the Blue House National Security Office. Currently, he is serving as a national defense coordinator in the Ministry of Foreign Affairs.

Man-Sung Yim

Man-Sung Yim is Donald E. Bentley and Agnes Muszynska Endowed Chair Professor in the Department of Nuclear and Quantum Engineering and director of the Nuclear Nonproliferation Education and Research Center at the Korea Advanced Institute of Science and Technology. Dr. Yim, whose work promotes safe and responsible use of nuclear energy, conducts research on the nuclear fuel cycle, nuclear-waste management, nuclear safety, nuclear nonproliferation, and nuclear-energy policy. He is currently a member of the Korean National Academy of Engineering and the Scientific Program Committee of the Comprehensive Nuclear-Test-Ban Treaty Organization. He serves as associate editor (Asia) of nuclear technology for the American Nuclear Society, an editor of the Journal for Peace and Nuclear Disarmament, and a member of the editorial advisory board of Progress in Nuclear Energy and the International Journal of Nuclear Security.