NAPSNet Policy Forum

Recommended Citation



DECEMBER 5, 2022


In this essay, CHEON Myeongguk explores the possible implications of the Ukraine conflict on the ROK attitudes regarding nuclear weapons. He concludes that the “ROK’s indigenous nuclear option would be a last resort as a deterrence measure against DPRK’s nuclear threat. This option would only be considered by the ROK if Donald Trump were reelected as President of the United States and decided to withdraw US forces from the Korean Peninsula and eventually withdraw the US nuclear umbrella protecting the ROK from DPRK aggression.”

CHEON Myeongguk is a visiting researcher at the Korea Institute for Defense Analyses (KIDA) working on DPRK weapons of mass destruction threats such as nuclear, chemical, and biological weapons and ballistic missiles. Deterrence, protection, counter measures, consequence management, and arms control are also included in his research scopes.

This essay is a contribution to the “Reducing the Risk of Nuclear Weapons Use in Northeast Asia” (NU-NEA) project, a collaboration between the Research Center for Nuclear Weapons Abolition, Nagasaki University, Nautilus Institute, and the Asia Pacific Leadership Network for Nuclear non-proliferation and Disarmament, is to reduce and minimize the risk that nuclear weapons will be used in the region by developing better understandings of the processes that could lead to the first use of nuclear weapons and the potential outcomes of such nuclear weapons use.  In the first year of this three-year project, the NU-NEA project team identified over 25 plausible nuclear weapons “use cases” that could start in Northeast Asia, sometimes leading to broader conflict beyond the region.  These nuclear use cases are described in the report Possible Nuclear Use Cases in Northeast Asia: Implications for Reducing Nuclear Risk. [1] The project has commissioned five contributions to update the cases in light of the Ukraine conflict, of which this essay is the fourth. This report is published simultaneously by APLN here and by RECNA-Nagasaki University here

The views expressed in this report do not necessarily reflect the official policy or position of the Nautilus Institute. Readers should note that Nautilus seeks a diversity of views and opinions on significant topics in order to identify common ground.

This report is published under a 4.0 International Creative Commons License the terms of which are found here.

Banner image: ROK Citizens’ Attitudes on Reintroducing US Tactical Nuclear Weapons to the ROK, ASAN Institute survey here



DECEMBER 5, 2022


In the Policy Forum essay that follows, Cheon Myeongguk explores the possible implications of the Ukraine conflict on the ROK attitudes regarding nuclear weapons.  He shows parallels between the geopolitical situations of Ukraine and the ROK, and suggests that Ukraine’s situation has underscored the need for the ROK to maintain strong military alliances and further develop its own conventional weapons capabilities. The lessons learned from the Ukraine conflict by the DPRK are also expected to further reduce the prospects for meaningful progress on talks of DPRK denuclearization, with establishment of a nuclear arms control regime on the Korean peninsula becoming one of the few remaining options for reducing the DPRK nuclear threat.  Although neither the attitudes of the ROK public nor the position of the ROK’s executive branch of government, with regard to re-deployment of US tactical nuclear weapons in the ROK or the ROK’s own acquisition of nuclear weapons have changed as a result of the Ukraine conflict, events including a 7th nuclear weapons test by the DPRK or a withdrawal of the US nuclear umbrella from the ROK could markedly shift those positions.

In the aftermath of the February, 2022 Russian invasion of Ukraine South Koreans (hereafter, Koreans) have absorbed a number of important national security lessons. First, the Russian invasion of Ukraine has shown the Republic of Korea (ROK) what could happen to a weaker country when it fails to maintain friendly relations with a stronger neighbor. For Koreans, the lesson has been that today’s liberal international order does not guarantee a nation’s sovereignty. As has been the case in Ukraine’s current and historical geopolitical circumstances, there have been many times in its history when the Korean Peninsula has suffered from its strong neighbors’ invasions or military threats. This experience has made Koreans eager to seek a credible ally and to build up its military capabilities in order to assure its defense. This drive to protect itself from potential adversaries in the region has made the ROK-United States alliance strong and led to the modernization of the ROK’s conventional forces in the period since the Korean War.

Prior to Russia’s 2022 invasion Ukraine had failed in building an effective deterrence and countering capability against a Russian military that has strong conventional and enormous nuclear forces. Witnessing this failure on the part of Ukraine, many Koreans have realized that it was a strategic mistake for Ukraine to relinquish the nuclear weapons and related delivery systems that it inherited following the breakup of the Soviet Union in 1990. The ROK should learn a lesson from the fact that prior to the Russian invasion, Ukraine had failed in making a credible ally to counter Russian aggression and in accomplishing the modernization of its conventional forces following giving up its nuclear forces. It is very likely that if Ukraine had retained its nuclear forces or had succeeded in making a strong military ally or in building a sufficient conventional military defense capability, it would not have been easily invaded by Russia. This should be an important lesson for countries with geopolitical disadvantages similar to those of Ukraine. This lesson should provide Korea with a rationale for maintaining its strong alliance with the United States and other partners, and in constructing an effective conventional military defense capability.

The Russian invasion of Ukraine illustrates the ROK’s two significant concerns in the denuclearization of the Democratic People’s Republic of Korea (DPRK), meaning convincing the DPRK to give up its nuclear weapons and dismantle its nuclear weapons production facilities, and in the development of the DPRK’s nuclear doctrine. The first concern regarding denuclearization of the DPRK is that seeing Ukraine’s experience following relinquishing the nuclear weapons it held, DPRK President Kim Jong Un could strengthen his negative views on denuclearization and retreat from the DPRK’s previous positions with regard to nuclear weapons negotiations. Consequently, the DPRK could consider its nuclear capability as a key security measure that should never be abandoned under any conditions or in any situation. This intransigence, which is becoming more and more evident, can be expected to make future negotiations on denuclearization of the Korean Peninsula much more difficult, and less likely to succeed. As the DPRK’s ambition to be a de facto nuclear country grows, its nuclear threat would become a constant to the ROK, which will feel that deterring DPRK’s nuclear threat is becoming more difficult. For the ROK, a major means of countering the DPRK’s nuclear threat comes from the extended nuclear deterrence provided to the ROK by the United States, grounded in the United States’ nuclear, missile defense, and conventional strike capabilities. The US nuclear capability, of course, is a dominant element in deterring DPRK nuclear attacks on the ROK. If the DPRK succeeds in developing an effective inter-continental ballistic missile (ICBM) that threatens the US continent, then the credibility of the United States’ extended deterrence will decline among the Korean people, and additional measures to assure the ROK of US dedication to the ROK’s defense would be demanded. Options for additional measures to secure the ROK from DPRK attack would probably include the redeployment of US nuclear weapons to the Korean Peninsula, the establishment of a nuclear planning group (NPG) including members from the ROK, and a “nuclear sharing” arrangement between the United States and the ROK.[1]

Another emerging challenge related to the reduced possibility, following the Ukraine conflict, that the DPRK’s denuclearization will take place, is whether the ROK will try to establish a nuclear arms control regime on the Korean Peninsula in order to make DPRK’s nuclear threat manageable. To improve the strategic stability of the Peninsula, it is not sufficient to merely deter DPRK’s nuclear threat, rather more proactive measures such as building a nuclear arms control regime are required. If a nuclear arms control regime on the Peninsula could be successfully established it would contribute to the strategic stability of the Peninsula and create a better environment for the eventual denuclearization of the Peninsula, and would also strengthen the nuclear arms control regime in North East Asia generally.  In order to make progress in nuclear arms control negotiations with the DPRK, it is necessary for the ROK and its allies to, in effect, accept the DPRK as a nuclear weapons state, which means a significant change in the ROK’s established diplomatic policy with respect to the DPRK’s nuclear weapons.

Russian President Vladimir Putin’s frequent statements referring, if usually indirectly, to using nuclear weapons on Ukraine further negatively affects the DPRK’s nuclear doctrine. Putin’s intention is to prevent NATO members from participating in the Ukraine war by threatening nuclear weapon use. From the ROK’s point of view, it seems like he has achieved his objective. Putin’s nuclear threat have made NATO members very cautious in their policies in providing military assistance to Ukraine and have made them more reluctant to support Ukraine. It is possible that Kim Jong Un would take a lesson from this in how to achieve the DPRK’s political objectives through the threat of use of nuclear weapons by adopting the Russian nuclear doctrine for the DPRK’s employment of nuclear weapons. For instance, in April 2022, Kim Jong Un stated that the DPRK’s nuclear weapons would be employed not only for deterring an adversary’s aggression but also for the maintenance of “fundamental national interests.”  This shift implies that the DPRK could employ its nuclear weapons more aggressively, even in peacetime, in order to forward the achievement of its political/strategic objectives. A more aggressive DPRK nuclear doctrine would jeopardize the ROK’s deterrence posture. Influenced by the Ukraine war, the DPRK’s need for the possession of nuclear weapons and its adoption of an aggressive nuclear doctrine become clearer to the ROK. This realization could stimulate the apprehensions of the Korean people and induce ROK policymakers to explore additional measures to enhance the credibility of United States extended deterrence and to improve the effectiveness of the ROK’s indigenous deterrent. The resulting arms race situation would also highlight the necessity of a nuclear arms control regime on the Korean Peninsula.

Many experts in the security policy communities of the ROK support the establishment of institutional measures such as a nuclear planning group (NPG) and a nuclear sharing arrangement, possibly including the redeployment of US tactical nuclear weapons, to strengthen the credibility and effectiveness of US extended deterrence on the Korean Peninsula. This support seems to be mainly in response to the DPRK’s continuing nuclear weapons and missile development activities including the recent abandonment of a moratorium on nuclear and ICBM tests.  The Ukraine war seems to have contributed to the solidification of Koreans’ continuing concerns about US extended deterrence. A public opinion survey in the ROK conducted by the Asan Institute for Policy Studies showed that 59% of Korean respondents supported the redeployment of US tactical nuclear weapons as of March 2022, compared with 61.3% in December 2020, 61.8% in December 2017, and 67% in December 2013.[2] This result shows that there is no meaningful relevance between Ukraine war and Korean opinion on the US extended deterrence, given that similar support for US nuclear weapons redeployment existed before the Ukraine war. This survey question, the results of which are shown in Figure 1, was designed to have respondents choose one of two options, support or oppose the reintroducing of US tactical nuclear weapons, regardless of other options.

Figure 1. ROK Attitudes on Reintroducing US Tactical Nuclear Weapons to the ROK[3]

Both the US and ROK governments are currently considering whether or not to deploy US strategic assets on the Korean Peninsula in the event that the DPRK conducts a 7th nuclear test. This kind of a measure could be helpful in demonstrating the alliance’s unified voice on the denuclearization of the DPRK, as well as, to some extent, to put pressure on China not to overlook on the DPRK’s provocations in the region. Nowadays, however, Koreans do not pay much attention to threatening behavior on the part of the DPRK (or China) because the threats from the DPRK are not new or temporary, rather have been ongoing for decades. Similarly, with regard to the re-introduction of US nuclear weapons to the ROK, the Ukraine war has not significantly changed Korean preferences for the deployment of US strategic assets. Regarding the policies of the new ROK administration on DPRK nuclear matters, President Yoon Suk-yeol’s government recently presented its policy position. It clearly stated that the administration does not consider the need for redeployment of US tactical nuclear weapon as long as the ROKUS alliance stays firm.  Instead, the government emphasized the need for demonstrations of US deterrence such as assuring the availability of strategic bombers, nuclear submarines, and aircraft carriers.

The impact of the Ukraine war on ROK public opinion as to whether the ROK should pursue indigenous nuclear weapons development also thus far seems to have been negligible. There has been no noticeable change in the degree to which the public supports ROK nuclear weapon development since the outbreak of the Ukraine war. Regarding whether the ROK should have its own nuclear weapons, a very high support rate in the ROK was observed even before the Russian invasion of Ukraine. This implies that a dominant variable on the support rate for indigenous nuclear capability is the DPRK’s ongoing nuclear threat. The combination of the DPRK’s six nuclear tests (as of November 2022), the failure of the 2019 Hanoi summit between Kim Jong Un and then-US President Donald Trump, and the recent breach of the DPRK’s self-moratorium on nuclear/ICBM tests have lowered the ROK public’s expectations on the possible denuclearization of DPRK, resulting in a high support rate for the ROK to possess its own nuclear capability. A survey sponsored by Asan Institute for Policy Studies shows that, the support rate for the ROK’s indigenous nuclear weapon development has been above 60%, for most of the past decade. Support even increased after the Hanoi summit in 2019, to a level close to 70%. The latest survey, conducted in March 2022, showed 70.2% or respondents in favor of the ROK developing its own nuclear weapons, which is just a 0.9% increase compared to the support rate (69.3%) in December 2020. It is unclear whether this tiny change is caused by the Ukraine war or events.[4]  Figure 2 shows the results over time of a survey question asking respondents to choose one of two options, support or oppose ROK indigenous nuclear weapon development regardless of other options.

Figure 2. ROK Public Attitudes on Indigenous Nuclear Weapon Development

The Yoon government’s policy toward an indigenous nuclear option seems clear. The current administration intends to continue to take the former administration’s position, which adheres to the ROK’s international obligations as a responsible NPT (Non-Proliferation Treaty) member state, as well as supporting the Joint Statement on the Denuclearization of Korean Peninsula agreed to by the DPRK and the ROK in 1992.[5]  The Yoon government pursues the strengthening of the effectiveness and credibility of US extended deterrence to deter the DPRK’s nuclear threat along, with improving the ROK’s conventional military capability, the Korean “conventional triad.” Since the DPRK’s first nuclear test in 2006, even though there have been many groups such as conservative politicians, academic societies, and thinktanks recommending the development of an ROK domestic nuclear capability, all ROK governments including the current Yoon administration have selected US extended deterrence as a realistic policy option to deter DPRK’s nuclear threat. This continuity shows that the ROK-US alliance has been functioning effectively in its role to support ROK security, as well as the trust that successive ROK administrations have placed in US commitments to the security of the Korean Peninsula and in US military capabilities.

However, if the DPRK conducts its seventh nuclear test, then debates on sensitive issues regarding nuclear weapons are expected to be reopened in ROK society. Issues that might be reopened include the re-introduction of US tactical nuclear weapons to the ROK, the establishment of a nuclear planning group, and the creation of a nuclear sharing arrangement between the ROK and US. It is likely that the Yoon government would seriously review the feasibility of these options for developing an enhanced posture of US extended deterrence on the Korean Peninsula. Nevertheless, the ROK’s indigenous nuclear option would be a last resort as a deterrence measure against DPRK’s nuclear threat. This option would only be considered by the ROK if Donald Trump were reelected as President of the United States and decided to withdraw US forces from the Korean Peninsula and eventually withdraw the US nuclear umbrella protecting the ROK from DPRK aggression.


[1] “Nuclear sharing” provides countries without nuclear weapons the protection afforded by nuclear weapons from another country.  For example, the North Atlantic Treaty Organization states “NATO’s nuclear sharing arrangements ensure that the benefits, responsibilities and risks of nuclear deterrence are shared across the Alliance.” (NATO, 2022, “NATO’s Nuclear Sharing Arrangements”, dated February 2022, and available as

[2] Asan Institute for Policy Studies (2022), “Press Release: Asan Institute Releases the Asan Report “South Korean Public Opinion on ROK-U.S. Bilateral Ties”, dated May 31, 2022, and available as

[3]  J. Kim et al, South Korean Public Opinion on ROK-U.S. Bilateral Ties, Asan Institute, May 31, 2022, p. 27 at: Figure 2 is from p.29.

[4] Asan Institute for Policy Studies (2022), “Press Release: Asan Institute Releases the Asan Report “South Korean Public Opinion on ROK-U.S. Bilateral Ties”, dated May 31, 2022, and available as

[5] See, for example, Ministry of Foreign Affairs (ROK, 2008), “Joint Declaration on The Denuclearization of The Korean Peninsula”, available as


The Nautilus Asia Peace and Security Network invites your responses to this report. Please send responses to: Responses will be considered for redistribution to the network only if they include the author’s name, affiliation, and explicit consent

nautilus-logo-smallThe NAPSNet Policy Forum provides expert analysis of contemporary peace and security issues in Northeast Asia. As always, we invite your responses to this report and hope you will take the opportunity to participate in discussion of the analysis.

Leave a Reply

Your email address will not be published. Required fields are marked *