Guest Contribution: Make the U.S.-ROK Alliance Stronger To Respond to North Korea’s Growing Nuclear Threat

A misrepresentation of North Korea’s intent toward denuclearization, combined with the three rounds of historic U.S.-DPRK summit talks in Singapore, Hanoi, and Panmunjom over the past three years, have given the impression as though there has been great progress in the peace and denuclearization of the Korean Peninsula. The fact of the matter, however, is that, as of now, not a single North Korean nuclear weapon has been dismantled, and there has been no reporting on or freezing of North Korean nuclear manufacturing facilities. More fundamentally, there is not even a consensus on the definition of “denuclearization.”

In his report to the Eighth Party Congress in January 2021, Kim Jong-un made it clear that the country would continue to strengthen its nuclear arsenals, formalizing the development and production of tactical nuclear weapons and the development of a 15,000km-range intercontinental ballistic missile (ICBM), multiple independently targetable reentry vehicle (MIRV) technology, and a strategic nuclear-powered submarine. North Korea in effect has already operationally deployed nuclear forces with which it can attack South Korea. It also has the capability to launch a nuclear attack against Japan and most U.S. bases in the western Pacific, including Guam. What should be our response in a situation where North Korea is even developing strategic nuclear weapons capable of threatening the continental United States?

The inauguration of the Biden Administration, which values alliances, is very fortunate for South Korea, because South Korea desperately needs a stronger ROK-U.S. alliance. Unlike the Trump Administration, which was more interested in political events, the Biden Administration is expected to aim for substantial denuclearization talks with North Korea. One thing that worries South Korea is the possibility of tacit U.S. recognition of North Korea as a nuclear state like India and Pakistan, while keeping North Korea’s denuclearization as a long-term goal.

Some experts advising the Biden Administration are of the position that the Iran nuclear deal should be applied to North Korea. Their rationale is that it is mission impossible to achieve North Korea’s denuclearization, and thus crisis management through a freeze and a phased approach is more realistic than complete denuclearization. They view nuclear arms control as a necessity for attaining the goal of denuclearization. Nuclear arms control is what Pyongyang has wanted for a long time, and while it may seem like a rational approach, it is contradictory in that it in effect recognizes North Korea as a nuclear weapon state. If we are to approach the North Korean nuclear issue from an arms control viewpoint, we risk becoming mired in North Korea’s strategy of winning recognition as a nuclear state by exchanging partial denuclearization, or nuclear arms control, for the lifting of key economic sanctions.

Against this backdrop, we, a study group (named as “Good Minds for the Korean Peninsula”) that consists of former ROK government officials, academics, and journalists, offer the following recommendations.

First, the ROK and the United States should maintain the goal of North Korea’s complete denuclearization and continue sanctions on North Korea. While pursuing a peaceful resolution of the North Korean nuclear issue through negotiations, we must never give up the goal of North Korea’s complete denuclearization. We, the study group participants, object to the premature lifting of sanctions in the name of provoking a nuclear arms control on the part of North Korea. The ROK and the U.S. need to make it clear to North Korea that sticking to its nuclear arsenals will come at a prolonged strategic price serious enough to hurt the regime. This is the single most important key to achieving North Korea’s denuclearization.
Second, the ROK and the U.S. should increase the credibility of the alliance and the nuclear umbrella. The U.S. nuclear umbrella, grounded in a solid ROK-U.S. alliance, remains the core deterrent against North Korea. Seoul should significantly reinforce policy coordination with the United States regarding the latter’s extended deterrence and nuclear umbrella. Seoul should re-establish a ROK-U.S. communication channel for close cooperation on extended deterrence, for one, by jump-starting the “Extended Deterrence Strategy and Consultation Group (EDSCG)” between South Korean and U.S. vice ministers of foreign affairs and defense. In addition, Seoul should work closely with Washington to chart a principled and effective “ROK-U.S. nuclear doctrine” on a nuclear umbrella and extended deterrence so that it will give concrete shape to the nuclear umbrella with which to prop up the doctrine.

The U.S. should consider redeploying tactical nuclear weapons in South Korea. In this vein, South Korea may need to review the possibility of deploying to the East Sea a U.S. nuclear submarine loaded with nuclear cruise missiles and placing it under the joint custody of allies. A U.S. nuclear asset jointly managed by the ROK and the United States would operate under the doctrine of striking Pyongyang by default, should Seoul come under a nuclear attack. Though a U.S. nuclear asset, the operating cost of the submarine would be shared among the two nations. By adopting a format similar to the North Atlantic Treaty Organization’s (NATO) political co-management (nuclear sharing), the two nations could enhance the credibility of the nuclear umbrella.

Third, South Korea should strengthen its missile defense by integrating ROK-U.S. intelligence assets. The ROK armed forces should build a non-nuclear deterrent with significantly increased missile defense and precision-strike capabilities. South Korea should seek a powerful deterrence strategy that combines deterrence through retaliation, as provided by the U.S. nuclear umbrella, with deterrence through defense, whose core is damage control through missile defense and precision strike capabilities. A powerful and effective deterrent is an absolute necessity for resolving the North Korean nuclear issue over the long term and in a peaceful manner.

South Korea has pursued an independent missile defense system, known as the Korea Air and Missile Defense (KAMD), with the rationale that joining a U.S.-led missile defense would amount to being integrated into the U.S. global strategy and thus provoke China. However, key U.S. allies, such as NATO countries and Japan, have jointly pursued and deployed missile defenses with the United States. South Korea without a doubt needs the U.S. military’s strategic assets to effectively deter North Korean nuclear and missile threats.

It is thus critical that South Korea urgently build a multi-layered defense system that will most efficiently protect the people by integrating South Korean and U.S. intelligence assets necessary for missile defense. In particular, it should work quickly toward bringing in a THAAD battery-level unit to defend highly populated metropolitan areas such as Seoul.

Finally, South Korea should adhere to a non-nuclear policy to the extent possible, but it should leave its nuclear options open. The hope for North Korea’s denuclearization is still pinned on the international community’s common interest in preserving the “global nonproliferation regime.” Recognizing or tolerating North Korea’s nuclear armament will in effect mean the end of the global nuclear non-proliferation regime. South Korea must stick to a non-nuclear policy to the extent possible, until the window of opportunity for negotiations closes. Yet, the U.S. and ROK also need to be prepared for the worst.

South Korea will have no choice but to pursue its own nuclear program if North Korea’s denuclearization becomes impossible through negotiations and if U.S. troops are withdrawn from South Korea and the ROK-U.S. alliance consequently disintegrates. To avoid this situation, South Korea and the U.S. must not give up on the goal of North Korea’s complete denuclearization until the very end, and we must do our best to enhance our negotiating leverage and build a deterrent through the ROK-U.S. alliance.

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Duk-min Yun is Professor at the Hankuk University of Foreign Studies and former Chancellor of The Korea National Diplomatic Academy. 

Sung-han Kim is Professor at Korea University and former Vice Minister of Foreign Affairs and Trade of the Republic of Korea. 

Cheol Hee Park is Professor at the Graduate School of International Studies and Director of the Institute of International Affairs at Seoul National University. 

The Korea Chair Platform is published by the Office of the Korea Chair ( program/korea-chair) at the Center for Strategic and International Studies (CSIS), a private, taxexempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s). The Office of the Korea Chair invites essays for consideration for the Platform. For inquiries, please email

Duk-min Yun

Professor, Hankuk University of Foreign Studies; former Chancellor of Korea National Diplomatic Academy

Sung-han Kim

Professor, Korea University; former Vice Minister of Foreign Affairs and Trade

Cheol Hee Park

Professor, Graduate School of International Studies, Seoul National University; Director, Institute of International Affairs, Seoul National University