South Koreans See Improved Security, Confident in US Security Guarantee

January 18, 2019

By: Dina Smeltz, Senior Fellow, Public Opinion and Foreign Policy; Karl Friedhoff, Marshall M. Bouton Fellow for Asia Studies; Lily Wojtowicz, Research Associate

Over the past 12 months, there have been more discussions between South Korean, US, and North Korean officials about Pyongyang’s potential denuclearization than at any time since the Six-Party Talks in 2006 and 2007. Exactly where those discussions are headed is unclear. But in South Korea, the public generally sees an improvement in the South Korean security situation according to a just-completed Chicago Council on Global Affairs survey. As a result, support for South Korea developing its own nuclear weapon appears to have waned, though a slight majority remains in favor. Despite what seems to be a slight sense of relief, the South Korean public is skeptical that either Moon or Trump can convince Kim Jong Un to fully denuclearize.

Key Findings:

  • A plurality of South Koreans (42%) say that their country’s national security situation has improved compared to four years ago.
  • A majority of South Koreans (57%) say President Moon had a greater influence on North Korea’s decision to hold denuclearization talks than did President Trump (31%).
  • But slim majorities have little or no confidence that either President Moon’s (52%) or President Trump’s (53%) negotiating abilities will result in the denuclearization of North Korea.
  • The US-South Korea alliance (36%) and US forces in Korea (20%) are the two most highly-cited factors in preventing a wide scale North Korean attack.
  • A narrow majority (54%) favor South Korea developing its own nuclear weapons, down from similar readings in recent years.

Plurality See Improvement in South Korean Security Situation

In August 2017, many around the world held their breath as Donald Trump and Kim Jong Un traded ominous barbs, including the now infamous “Fire and Fury” tweet. In the meantime, South Korean President Moon Jae-in laid the groundwork to pursue increased interactions with Pyongyang. Kim Jong Un’s 2018 New Year speech provided an opening, and President Moon eventually facilitated a meeting between Trump and the North Korean leader. The series of summits appear to have assuaged South Korean public concerns. According to the results of a December 26-27 Chicago Council survey, a plurality of South Koreans say that their country’s national security situation has improved over the past four years (42%), three in ten (30%) believe the security situation has remained the same, and 23 percent say it has worsened.


However, there are significant partisan divides. A majority of those who identify as supporters of the Democratic Party (DP)—the party of President of Moon—say the security situation has improved (66%) versus 13 percent of supporters of the opposition Liberty Korea Party (LKP). Partisan divides on this issue are to be expected, but it is worth noting that there may be broader agreement on North Korea policy overall under the Moon administration. In a March 2018 poll conducted by the Asan Institute, 60 percent stated satisfaction with Moon’s policy towards the North. [1]

From Confrontation to Negotiation

The speed of rapprochement, from a potential confrontation in late 2017 to a series of summits in 2018, left many analysts debating whether Moon Jae-in or Donald Trump deserved credit for the turnaround. While a July 2018 Asan poll found that South Koreans rated Trump the most likeable leader included in the survey (5.2),[2] they assign most of the credit to Moon Jae-in. Six in ten say his outreach has had a greater impact on the current talks about denuclearizing North Korea (57%) compared to just three in ten who believe Trump has had more influence (31%).[3]

South Koreans Skeptical about North Korea Denuclearization

Despite a plurality seeing an improvement in South Korea’s security, the South Korean public is skeptical that Pyongyang will ever give up its nuclear weapons program, according to a March 2018 Korean Gallup poll (64%).[4] Accordingly, there is similar skepticism in the abilities of either Moon (52% lack confidence) or Trump (53% lack confidence) to persuade North Korea to abandon its nuclear program.[5] Even if either leader could convince North Korea to denuclearize, the public has ambiguous expectations of just how long denuclearization will take. A June 2018 East Asia Institute poll shows that 46 percent said denuclearization would take a long time.[6] Similarly, the March 2018 Asan poll found that among those that thought North Korea would denuclearize—24 percent said North Korea would not denuclearize—18 percent said it would take between 6 and 10 years.[7]

Three-quarters (76%) of the South Korean public views international sanctions against North Korea to be a positive factor in attempts to pressure North Korea to denuclearize. This result is largely consistent across age cohorts, political party affiliation, and ideological outlook.

Koreans See US-ROK Alliance as the Key Deterrent to North Korean Attack in Past Decade

The rhetoric emanating from North Korea often comes with threats of violence, and at times, there have been limited attacks against South Korea. But there has not been a larger-scale invasion. South Koreans attribute the relationship with the United States as the main factor in preventing a wide scale North Korean attack in the past 10 years. The US-South Korea alliance (36%) and US forces stationed in Korea (20%) are the most often cited reasons in the survey. Results for both of these items are highly consistent across age groups. A further 7 percent say that the key to preventing an attack has been the US nuclear umbrella.


The South Korean public not only considers the US-South Korea alliance an effective bulwark against a North Korean attack, they are also confident in the US security guarantee. Fully 75 percent of the South Korean public is very (30%) or somewhat (45%) confident that the United States would defend South Korea if North Korea attacked. This corresponds with a Pew Spring 2017 survey in which an even higher percentage of South Koreans (91%) believed that if South Korea got into a serious military conflict with North Korea, the United States would use military force to defend their country.[8]

Even if North Korea agrees to abandon its nuclear program, six in ten Koreans believe that South Korea will need to continue military exercises with the United States (60%). But there is less consensus on whether they would need to remain under the protection of the US nuclear umbrella (51% no, 45% yes). Survey data from the East Asia Institute show that the Korean public is also closely divided on whether US Forces Korea would still be necessary after “peace and unification occur” (50% yes, 45% no).

Waning Support for a Nuclear South Korea

Once taboo, discussion of a South Korean domestic nuclear weapons program has become an issue now more openly discussed. As in past polls conducted in the country, a slight majority of the Korean public believe that South Korea should develop its own nuclear weapons (54% yes, 43% no). Compared to a similarly-worded question asked in previous Asan polls, this support has dropped since 2011-2013 surveys when two-thirds of Koreans approved of obtaining their own nuclear weapons.[9] 

This shift is also apparent in East Asia Institute trends. In their 2018 poll, the East Asia Institute found that 43 percent of South Koreans would support South Korea developing its own nuclear weapons program if North Korea does not agree to give ups its nuclear weapons, down from 67 percent in 2017.[10] The public seems to acknowledge the risks of a domestic South Korean nuclear program. While majorities see clear benefits in reducing South Korea’s dependence on the US (61%), in allowing  South Korea to respond to a North Korean threat (57%), and in terms of increasing its regional power (53%) if it were to pursue nuclear weapons, these advantages are outweighed by potential hazards. Even larger majorities are convinced that obtaining these weapons would trigger an arms race in the region (69%), especially with Japan (79%), and would also precipitate economic hardship for South Korea due to likely international sanctions (67%). 

(Click for full size.)

This survey is a project of the Lester Crown Center on US Foreign Policy, and is made possible by the generous support of the John D. and Catherine T. MacArthur Foundation.

About the Survey

This survey was conducted in South Korea from December 26–27, 2018 by Hankook Research. The sample size was 1,000 aged 19 and older and it employed RDD for mobile and landline phones. The margin of error is ±3.1% at the 95% confidence level.

About the Chicago Council on Global Affairs

The Chicago Council on Global Affairs is an independent, nonpartisan membership organization that provides insight—and influences the public discourse—on critical global issues. We convene leading global voices, conduct independent research, and engage the public to explore ideas that will shape our global future. The Council is committed to bringing clarity and offering solutions to issues that transcend borders and transform how people, business, and governments engage the world. Learn more at and follow @ChicagoCouncil.


[1] “South Koreans and Their Neighbors 2018”, The Asan Institute for Policy Studies, March 2018. By comparison, in 2014 only 42% approved of the Park administration’s North Korea policy.

[2] Kim Ji-eun, “South Korean public opinion on Kim Jong-un and Trump more favorable after Singapore summit,” Hankyoreh, July 9, 2018.

[3] Five percent of respondents said both leaders are equally responsible and 8 percent say neither was responsible.

[4] Gallup Korea Daily Opinion No. 298, March 13-15, 2018. This was down from 90 percent in January 2018.

[5] Just under half are at least somewhat confident in Moon (45%) or Trump (44%).

[6] “The 6th South Korea-Japan Joint Public Opinion Poll (2018)”, The Genron NPO & East Asia Institute, June 18, 2018.

[7] “South Koreans and Their Neighbors 2018”, The Asan Institute for Policy Studies, March 2018. A plurality (24%) said North Korea would not denuclearize.

[8] Kristen Bialik, “5 facts about how the US and its allies see North Korea,” Pew Research Center, June 11, 2018.

[9] Kim Jiyoon, Karl Friedhoff, and Kang Chungku, “The Fallout: South Korean Public Opinion Following North Korea’s Third Nuclear Test,” The Asan Institute for Policy Studies, February 25, 2013.

[10] “The 6th South Korea-Japan Joint Public Opinion Poll (2018)”, The Genron NPO & East Asia Institute, June 18, 2018.


South Koreans See Improved Security, Confident in US Security Guarantee

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