N. Korea Policy And Deterrence

The war in Ukraine has had multiple impacts on the Korean peninsula. It has reminded South Korea of the strategic importance of the U.S.-ROK alliance as a buffer against hostility from outside powers, while also intensifying concerns about South Korea’s vulnerability as a nuclear-weapons-free power facing a nuclear-armed North Korea. For North Korea, the war in Ukraine seems to have amplified the importance of nuclear weapons for its security while prompting Pyongyang to consider a new “first-use” nuclear doctrine as well as the operational deployment of tactical nuclear weapons — imitating Putin’s tactics in Ukraine.

The war in Ukraine has also produced a favorable external environment for North Korea’s continued development of its nuclear and missile programs. North Korea’s increasing weapons capabilities, its threats to use nuclear weapons for offensive purposes, and the vulnerability of U.S. national missile defense interceptors to North Korean multiple independent reentry vehicle technologies have led the South Koreans to question the credibility of U.S. extended deterrence.

Collectively, these shifts in the strategic landscape call for the United States and its allies to reexamine traditional approaches to the North Korea nuclear issue and devise ways to increase the credibility of U.S. extended deterrence. The recent election of South Korean president Yoon Suk Yeol, whose positions on North Korea and regional issues align closely with those of the Biden administration, presents opportunities for the alliance to pursue new initiatives that will enhance the stability, security, and prosperity of the region.

This report presents actionable recommendations for navigating North Korea policy and strengthening U.S. extended deterrence during these uncertain times.

ON NORTH KOREA

North Korea is unlikely to return to diplomacy until it achieves its weapons development goals explicated in recent speeches. Nonetheless, the allies should map out policies that prepare for whatever actions Pyongyang may take in the coming weeks and months.

Prepare for an eventual return to negotiations, with low expectations for short-term breakthroughs.

• Devise roadmaps toward complete and verifiable denuclearization that include interim steps to reduce threat levels and build confidence.

• Signal openness to diplomacy and continued readiness to talk without preconditions.

Enhance defense, deterrence, and sanctions enforcement.

• To strengthen deterrence and defense:

  • Resume joint military exercises that had been suspended or downgraded in previous negotiations.

  • Support South Korea’s military improvements, including the Kill Chain, early deployment of Iron Dome, directed energy possibilities, upgraded ship-based defenses, and an additional Terminal High Altitude Area Defense (THAAD) battery — moving South Korea to the top of the list for its purchase, given the urgency of the North Korean missile threat.

  • Expand U.S.-ROK space cooperation to strengthen reconnaissance capabilities.

  • Do not, under current circumstances, deploy U.S. tactical nuclear weapons to the Korean peninsula nor condone the acquisition of nuclear weapons by South Korea.

• Develop a broad counter-missile strategy that focuses on detecting and defending against North Korean missiles and launchers, disrupting its capability networks, and destroying its launchers and missiles.

  • Investigate new concepts of missile defense, such as boost-phase systems that would help overcome the limitations of current systems.

• Increase trilateral defense coordination among the United States, South Korea, and Japan.

  • Reinstate the Trilateral Consultation and Oversight Group as a regular channel of communication and policy coordination on North Korea.

  • Consider additional forms of military cooperation to deter North Korea, including information sharing, anti-submarine warfare, missile defense, contingency planning, and regular trilateral exercises.

• Bolster sanctions enforcement.

  • Lead efforts, together with Japan, to enforce existing North Korea sanctions, including deterring illegal ship-to-ship transfers and pressuring countries to return North Korean laborers working overseas in violation of international sanctions.

  • Be ready to offer sanctions lifting but only for substantive and difficult-to-reverse steps on denuclearization by North Korea.

  • Expand secondary sanctions against China and Russia if they do not comply with UN Security Council Resolutions.

Communicate positions on humanitarian assistance and human rights as separate from denuclearization diplomacy.

• Consider immediate humanitarian assistance to North Korea through the international aid community to improve conditions for North Korean citizens.

• Appoint a U.S. special envoy for North Korean human rights.

ON U.S. EXTENDED DETERRENCE

The U.S. extended deterrence commitment to South Korea involves two central purposes: to deter North Korean aggression, and to prevent nuclear proliferation. The commitment has physical and psychological aspects that both affect its credibility. As such, extended deterrence requires consistent U.S. demonstrations and assurances of both capabilities and will.

Avoid policies that put the two purposes of extended deterrence into conflict, for instance, by advancing deterrence but setting back nonproliferation efforts.

Provide reassurance and clarification on existing and new U.S. capabilities.

• Emphasize that the U.S.-ROK “community of fate” — referring to the 28,500 U.S. troops in South Korea that tie the country together with the United States strategically — forms the core of extended deterrence, regardless of additional U.S. capabilities that may be introduced.

Improve joint planning and execution.

• Create a framework for joint nuclear planning, similar to a North Atlantic Treaty Organization (NATO) planning group.

• Sustain practices such as sending a senior South Korean liaison officer to U.S. Strategic Command.

• Reactivate the high-level Extended Deterrence Strategy and Consultation Group (EDSCG).

• Streamline protocols for direct Space-Based Infrared System access to South Korea in addition to the geographic commanders, as the United States does for Israel and Japan.

Supplement U.S. extended deterrence dialogues with South Korea and Japan with a track 1.5 trilateral strategic exchange in order to stay informed about developments in each country and identify opportunities for coordination

Pursue U.S. military adjustments and improvements.

• Change the regional strategic and nuclear posture to allow for more robust and constant demonstrations of U.S. capabilities.

  • This could entail the continuous presence in the region of either U.S. submarines equipped with nuclear cruise missiles or strategic bombers or investing in infrastructure in South Korea to receive U.S. dual-capable aircraft.

• Improve U.S. national missile defense capabilities vis-à-vis North Korea, including through accelerating plans to deploy interceptors equipped with Next Generation Interceptor technology and investing in boost-phase missile defense technologies.

• Restore funds for and continue pursuing the U.S. nuclear sea-launched cruise missile program.

Lay pre-decisional groundwork for possible redeployment of U.S. low-yield nuclear weapons at some point in the future.

• Consider allied tabletop planning exercises that would be explicitly pre-decisional and leave the timeline and scope of weapons deliberately ambiguous.

• Calibrate decisionmaking to shifts in the security environment and the North Korean threat level.

Introduction

Reorienting the Alliance in a Shifting Global Landscape

The world is experiencing a number of tectonic shifts that present new challenges for the U.S.-ROK (Republic of Korea) alliance and reinforce its importance as a basis for peace and stability in Northeast Asia. The aftershocks of the Covid-19 pandemic have roiled international commercial markets and raised new questions about supply chain resilience, prompting major industries to consider fundamental changes to future plans. Chinese president Xi Jinping’s increasingly active management of China’s economy is creating new geopolitical risks for international businesses. And tightening relations between China and Russia — solidified with Xi and Vladimir Putin’s declaration at the Beijing Olympics of a partnership with “no limits” — point to a global geopolitical realignment that will be reinforced by economic trends.

The war in Ukraine, following Russia’s unprovoked invasion on February 24, has monumentally impacted world politics and Asia. The war has made Russia weaker militarily and economically (due to the impact of unprecedented sanctions) but also more dangerous, as a declining power willing to take on more risks. China’s support for Russia has diminished its soft power as a defender of sovereignty and territorial integrity while increasing its vulnerability to secondary sanctions it cannot afford due to its own mounting economic problems. And the United States is now focused on Europe and needs to recalibrate its global strategy even as China remains its pacing threat.

As the world becomes more bifurcated between authoritarian and democratic powers, the war in Ukraine has several implications for the United States and its allies: a shifting balance of power due to Russia’s decline; complication of Xi’s designs on Taiwan given Moscow’s multiple failures and heavy sanctions; greater U.S. and Japanese attention to reinforcing deterrence in the Taiwan Strait; greater cohesion among democratic countries; heightened unity of purpose and appreciation for the liberal international order as a foundation for global peace and stability; and the undermining of the Xi-Putin narrative that the future lies with China and Russia.

This degree of change presents a perilous and uncharted landscape but also new opportunities for coalition building for Washington and Seoul to navigate in the coming months. Since this group last met in early 2021, the U.S.-ROK alliance has made significant progress in tackling some of the headwinds that have previously held the relationship back from its full potential. During the early months of the Biden administration, contentious issues such as negotiations over the Special Measures Agreement were resolved, paving the way for a successful summit between Presidents Joe Biden and Moon Jae-in in May 2021 and the release of a comprehensive U.S.-ROK Leaders’ Joint Statement that advocated for deeper cooperation across several dimensions of the relationship. The recent election of South Korean president Yoon Suk Yeol, whose positions on Japan, North Korea, China, and Indo-Pacific strategy align closely with Washington, will enhance the alliance’s effectiveness in dealing with the region’s most pressing challenges. The successful first summit of the two leaders in May 2022 laid out an ambitious agenda for Washington and Seoul as President Yoon seeks to build South Korea’s role as a global player and supporter of the rules-based international order. Channeling these shared perspectives into concrete initiatives that will enhance the stability, security, and prosperity of the region during a period of compounding uncertainties will be the central challenge for the alliance in the year ahead.

This degree of change presents a perilous and uncharted landscape but also new opportunities for coalition building for Washington and Seoul to navigate in the coming months.

Implications of the War in Ukraine for the Korean Peninsula

In addition to its broader global and regional implications, the war in Ukraine has had multiple impacts on the Korean peninsula, with varied takeaways for the alliance.

For South Korea, Russia’s invasion of Ukraine sparked a strong response at the societal level — with individuals and civic groups rallying to support Ukraine and condemn Russia’s actions — as well as a strengthened appreciation for the importance of liberal values in a country’s foreign policy to promote stability and security. The war has also reminded South Koreans of the strategic importance of the U.S.-ROK alliance, grounded in shared values as well as security guarantees that decrease the chances that South Korea will find itself in Ukraine’s situation. For alliance managers in Seoul and Washington, the war in Ukraine has validated the importance of focusing on military readiness before a threat is realized, rather than after. All of these effects should help to fortify the U.S.-ROK alliance.

At the same time, the war in Ukraine has intensified concerns among South Koreans about their vulnerability as a nuclear-weapons-free power facing a nuclear-armed North Korea, particularly given the possibility that new leadership in the United States in the coming years might, again, consider U.S. troop withdrawals as the Trump administration did. While the Yoon government will manage this concern through strengthening extended deterrence with the United States and trilateral coordination with the United States and Japan, policy discussions within South Korea are likely to continue to feature a range of suggestions to reduce South Korea’s vulnerability, such as the rotation of dual-use strategic assets, redeployment of U.S. tactical nuclear weapons, and introduction of a nuclear sharing plan on the peninsula in the style of the North Atlantic Treaty Organization (NATO).

The war in Ukraine seems to have underscored for North Korea the importance of nuclear weapons for its security. Whether this is the correct conclusion or not, the regime reiterated its nuclear ambitions in April 2022, thereby decreasing prospects for denuclearization. North Korea drew a similar lesson from the Iraq, Libya, and Afghanistan cases. Again, whether correct or not, North Korean officials stated with conviction during the Six Party Talks in 2006 that the United States would not have attacked a nuclear-armed Iraq or Afghanistan (implying the same for a nuclear-armed North Korea).

North Korea has also noted Putin’s threat to use nuclear weapons to deter NATO’s intervention in Ukraine. At a military parade on April 25, Kim Jong-un noted that “our nukes can never be confined to the single mission of war deterrent” and suggested that he would consider the pre-emptive use of these weapons to deter threats from outside forces or to gain superiority in a conventional conflict. These statements seemed to reveal a new “first-use” nuclear doctrine for Pyongyang in which the threat of nuclear weapons could be used to deter the United States from intervening in any armed conflict on the Korean peninsula, mirroring Putin’s moves in Ukraine. The possibility of North Korea’s development and operational deployment of tactical nuclear weapons, in particular, has heightened concerns among South Koreans regarding the reliability of U.S. extended deterrence and amplified calls for the redeployment of U.S. tactical nuclear weapons on the peninsula.

The final implication of the war in Ukraine for Korea is the favorable external environment it has produced for North Korea’s continued development of its nuclear and missile programs. Previously, Beijing and Moscow were willing to join forces with the United States and its allies to punish North Korea following its provocations, even as they helped North Korea evade sanctions. Since the start of the war in Ukraine, however, Beijing and Moscow have refused to enforce existing sanctions and vetoed any further actions against North Korea in the UN Security Council. Given this situation, additional nuclear tests by North Korea would be unlikely to prompt a serious reaction from China and Russia. This marks a critical juncture in regional dynamics — with Beijing and Moscow now viewing Pyongyang’s provocations more as a means to gain advantages over Washington than a concerning threat to regional stability.

Collectively, these shifts in the strategic landscape call for the United States and its allies to (1) reexamine traditional approaches to the nuclear issue in the diplomatic and military realms and (2) devise ways to enhance the credibility of U.S. extended deterrence in order to reduce South Korea’s (and Japan’s) sense of vulnerability.

North Korea’s Actions and Objectives

Pyongyang was relatively quiet during the first year of the Biden administration. This could be a result of severe internal difficulties due to its strict Covid-19 lockdown and ongoing economic challenges or because it wanted to find out if the Biden administration might consider lifting the sanctions that Pyongyang had aimed to negotiate an end to during the failed 2019 Hanoi summit.

Since the start of 2022, however, North Korea has embarked on an extensive missile testing campaign, conducting missile launches on 22 separate occasions, ranging from short-range hypersonic missiles to intercontinental ballistic missiles (ICBMs). These tests have helped North Korea make significant advances toward its aim of achieving a reliable capability to penetrate U.S. missile defenses and strike the U.S. homeland. Pyongyang could then use this capability to deter a U.S. attack on North Korea while generating doubts among U.S. allies in the region that Washington would put one of its own cities at risk by responding to a North Korean attack on an ally. North Korea also likely aspires to employ tactical nuclear weapons as an asymmetric capability to fundamentally change the balance of power on the Korean peninsula in its favor, enabling Pyongyang to dictate the terms of interaction with South Korea in the economic, security, and political spheres.

Kim Jong-un laid out his weapons development objectives in unusual detail in his January 2021 remarks at the Eighth Party Congress of the Workers Party of Korea (see Box 1). At the April 25 military parade, Kim reiterated his determination to improve the country’s nuclear capabilities “in terms of both quality and scale.” His ultimate goal is to achieve credible, albeit rudimentary capabilities to build three legs of a potential nuclear triad, as well as a tactical nuclear weapons capability.

Box 1: Excerpts from Summary of Kim Jong-un’s Remarks on Weapons Development during the January 2021 Eighth Party Congress of the Workers’ Party of Korea

Recalling that the Party Central Committee decided to develop a global strike rocket with more powerful warheads and an improved warhead control system and carried out this historic task by relying on the patriotism and loyalty of national defence scientists, the report affirmed that the new-type gigantic rocket on an 11-axis self-propelled launcher displayed during the military parade in celebration of the 75th founding anniversary of the Party fully demonstrated the ultra-modernity and great striking capability of our nuclear force.

The national defence science sector developed the super-large MLRS, a super-power attack weapon the world’s weaponry field had never known, and proceeded to develop ultra-modern tactical nuclear weapons including new-type tactical rockets and intermediate-range cruise missiles whose conventional warheads are the most powerful in the world.

The report also noted that in the period under review the sector of national defence scientific research was conducting research into perfecting the guidance technology for [a] multi-warhead rocket at the final stage, finished research into developing warheads of different combat missions including the hypersonic gliding flight warheads for new-type ballistic rockets and was making preparations for their test manufacture.

The report made public with pride that the standard of the goal in the modernization of medium-sized submarine was set correctly and it was remodeled experimentally to open up a bright prospect for remarkably enhancing the existing subsurface operational capabilities of our navy, that the design of new nuclear-powered submarine was researched and was in the stage of final examination and the designing of various electronic weapons, unmanned striking equipment, means of reconnaissance and detection and military reconnaissance satellite were completed, and that other achievements were made in national defence research of gigantic significance in developing the People’s Army into a powerful one with the strongest military muscle in the world.

It is necessary to develop the nuclear technology to a higher level and make nuclear weapons smaller and lighter for more tactical uses. This will make it possible to develop tactical nuclear weapons to be used as various means according to the purposes of operational duty and targets of strike in modern warfare, and continuously push ahead with the production of super-sized nuclear warheads.

The report also set a goal of attaining an advanced capability for making a preemptive and retaliatory nuclear strike by further raising the rate of precision good enough to strike and annihilate any strategic targets within a range of 15,000 kilometres with pinpoint accuracy.

And the tasks were brought up to develop and introduce hypersonic gliding flight warheads in a short period, push ahead with the development of solid-fuel engine-propelled inter- continental underwater and ground ballistic rockets as scheduled, and possess a nuclear- powered submarine and an underwater-launch nuclear strategic weapon which will be of great importance in raising the long-range nuclear striking capability.

The report also referred to the need to secure the ability of reconnaissance and information gathering based on operation of a military reconnaissance satellite in the near future, and conduct in real earnest the most important research to develop reconnaissance drones and other means of reconnaissance capable of precisely reconnoitering up to 500 km deep into the front.

Making the military equipment intelligent, precise, unmanned, high-performance and light should be set as the priority target of the munitions industry, and research and development be oriented to this end.

▲ Source: “On Report Made by Supreme Leader Kim Jong Un at Eighth Party Congress of WPK,” National Committee on North Korea, January 9, 2021.

North Korean behavior and rhetoric suggest that missile and nuclear tests will continue in the coming weeks and months. Externally, as noted above, North Korea faces a favorable environment for weapons development, with the United States focused on the war in Ukraine and China and Russia more closely aligned and unwilling to impose sanctions on North Korea following provocations. China and Russia are also as amenable as ever to facilitating North Korea’s evasion of sanctions so that Pyongyang can acquire necessary components for its weapons programs. The intensification of U.S.-China competition also benefits North Korea, as China is more willing to support North Korea, regardless of its behavior, in order to secure Pyongyang’s allegiance against the United States.

Internally, North Korea is dealing with a deepening economic crisis and poor health conditions, made more severe by the outbreak of Covid-19. These hardships also incentivize continued testing because displays of military prowess can help the regime boost loyalty and morale among the population during difficult times.

North Korea faces a favorable environment for weapons development, with the United States focused on the war in Ukraine and China and Russia more closely aligned and unwilling to impose sanctions on North Korea following provocations.

Lastly, North Korea’s continued military provocations serve to increase the possibility of drawing the newly elected Yoon administration and the alliance into a crisis that could lead to sanctions relief or other concessions desired by North Korea. Even absent a crisis, continued testing will increase North Korea’s potential bargaining leverage for an eventual return to diplomacy. Most experts agree that Pyongyang is not likely to return to diplomacy anytime soon. However, after North Korea is satisfied with its capability advancements, it may attempt to negotiate a testing moratorium in exchange for sanctions relief. Ending sanctions likely remains the top aim for Pyongyang. Among other things, it would relieve pressure on the regime following its ill-fated efforts to rebuild the economy through a path of “self-reliance,” which remains unlikely to succeed.

Specific capabilities to watch for in upcoming tests include continued nuclear testing (perhaps of a smaller, lighter weapon that could fit on top of a missile); multiple independent reentry vehicles (key to frustrating the missile defense systems of opponents); additional tests of submarine-launched ballistic missiles; and development of air-launched cruise missiles (an additional leg of a potential North Korean triad).

Building Core Strategic Principles to Guide North Korea Policy

Unlike President Biden’s China strategy, as elucidated by Secretary of State Antony Blinken on May 26, 2022, the administration has not provided a full public explication of its North Korea strategy. The classified policy review by the government completed in spring 2021 has not yet been presented in a speech or document. Nevertheless, some of the core tenets of the policy can be gleaned from statements by administration officials. First, the United States seeks complete denuclearization of the Korean peninsula. Second, the basis of any policy is a position of strength based on enhanced military readiness and improved defense and deterrence capabilities. Third, the United States is not opposed to diplomacy; on the contrary, it is willing to engage “any time, any place, anywhere” with North Korea, without preconditions. The focus of diplomacy is not an “everything for everything” deal of the type sought by former president Donald Trump, though the United States is willing to pick up the themes laid out in the first Trump-Kim summit and the Singapore Declaration of 2018 (i.e., denuclearization, peace regime, normalization of political relations, and return of prisoners of war/missing in action [POW/MIA] remains). The administration is not continuing the “strategic patience” policies of non-dialogue during the Obama years. Instead, officials describe their policy as a pragmatic, calibrated approach based on substantive negotiations aimed at denuclearization. The current state of non-dialogue in the negotiations, resembling the Obama years, is not for lack of U.S. efforts but stems from the absence of interest from North Korea (reportedly, nearly 20 attempts have been made by the Biden administration). Fourth, Biden has not ruled out a meeting with the North Korean leader provided that it would cap a serious and substantive negotiation and deliverable. Fifth, the United States is open to humanitarian assistance that would help North Koreans, and this assistance would not be tied to progress on denuclearization. Sixth, the United States supports Japan’s desire for a satisfactory resolution of the abduction issue and a return to the Pyongyang Declaration of September 17, 2002.

Having assumed office only in May 2022, the newly elected Yoon administration outlined its “audacious” plan (담대한 구상/damdaehan gusang) for denuclearization in August 2022. First, the goal is the complete and irreversible denuclearization of North Korea. Second, South Korea seeks stronger military readiness with the United States and a bolstering of extended deterrence capabilities. Third, in achieving denuclearization, the government will undertake a “principled” approach that involves employing pressure for denuclearization and nonproliferation, as well as sanctions for human rights abuses in North Korea, but also offering North Korea economic benefits and political normalization. Related to the latter point, the fourth tenet is that South Korea supports a peace regime, but only as the exit point to diplomacy, not the entry point. Fifth, South Korea supports humanitarian engagement and a “green” détente in inter-Korean environment and ecology issues, separate from denuclearization negotiations. This includes the provision of food and medicine in return for minerals purchases, as well as support for transportation and energy infrastructure development in North Korea, with a firm commitment from Pyongyang to denuclearization.

Though offered in different frames, the Biden and Yoon approaches to North Korea share many similarities — more than between Biden and the previous South Korean government — in terms of the core goals of denuclearization, sanctions pressure, and bolstered defense and deterrence capabilities. At the May 2022 summit meeting, the two leaders demonstrated the overlap in their policies. As President Yoon noted in his opening remarks at the joint press conference following the summit meeting, “We, as the leaders of the two countries, reiterated our common goal of the complete denuclearization of the DPRK. There is no compromise for security. Under this shared belief, we concurred that strong deterrence against North Korea is paramount.”

North Korea’s disinterest in engagement should not discourage allied action. Whether diplomacy returns tomorrow or one year from now, the allies should internalize key strategic principles and map out policies going forward. With the election of the Yoon government, there is a moment of policy unity between Washington and Seoul that should be used to prepare for whatever actions Pyongyang may take in the coming weeks and months.

With the election of the Yoon government, there is a moment of policy unity between Washington and Seoul that should be used to prepare for whatever actions Pyongyang may take in the coming weeks and months.

Policy Recommendations on North Korea

Strategic Principles

The following strategic principles should guide allied policies with respect to North Korea. Agreement on and internalization of these principles will ensure that, amid the coming unexpected twists and turns of diplomacy, crises, and even conflict, the two allies will remain focused on key common goals and preservation of a strong, united alliance. Straying from these principles for short-term gains is not in the mutual interests of Seoul and Washington.

The ultimate policy objective is to achieve complete and irreversible denuclearization. While there may be interim steps along the way, the two allies should work toward this final goal.

There should be no surprises between the allies. The temptation to engage in and attain marginal benefits from secret bilateral negotiations with North Korea (part of Pyongyang’s tactics to split the U.S.-ROK alliance) should be weighed against the damage done to trust in the alliance.

The core of any negotiation strategy with North Korea is a strong alliance, measured in terms of readiness and defense and deterrence capabilities. Neither ally should be willing to trade away alliance equities (e.g., cessation of military exercises) for short-term steps by North Korea. Strong U.S.-Korea-Japan trilateral policy coordination is an integral part of defense and deterrence capabilities. The allies should devise a range of actions to maintain the credibility of U.S. extended deterrence under shifting conditions (detailed further in the following section).

The United States and South Korea will support inter-Korean engagement that is accomplished in conjunction with steps on denuclearization. While South Korea should have some leeway to pursue engagement with North Korea, both allies must internalize that there will be no true peace and reconciliation on the Korean peninsula without the removal of the nuclear threat.

The United States and South Korea will support humanitarian assistance and improved human rights in North Korea separate from denuclearization. Such assistance, monitored by the international community, helps improve the human condition and conveys compassion and non-hostile intent on the part of the United States to the North Korean people.

The core of any negotiation strategy with North Korea is a strong alliance, measured in terms of readiness and defense and deterrence capabilities.

The North Korean nuclear threat is a regional and global security problem. While the United States and South Korea are key interlocutors, the nuclear threat engages the interests of all actors in the region, as well as the Treaty on the Non-Proliferation of Nuclear Weapons and the United Nations. The allies should seek to engage new partners in the region and beyond who have the means and will to increase pressure on North Korea to denuclearize.

China is a critical player on denuclearization, but the United States and South Korea should not depend on Beijing’s cooperation or cave to Chinese pressure tactics. Given that China’s interests with respect to North Korea have increasingly diverged from those of the United States and South Korea, Chinese pushback should be anticipated and Beijing should not be expected to act with regard to anything but short-term self-interest and transactional politics. Allied actions to strengthen deterrence vis-à-vis North Korea will complicate China’s regional ambitions, potentially prompting Beijing to reconsider its permissive attitude toward Pyongyang’s provocations.

SPECIFIC NORTH KOREA POLICIES (PURSUANT TO THE PRINCIPLES)

Because North Korea is unlikely to return to diplomacy until it achieves its weapons development goals, the United States and South Korea should pursue policies along three tracks:

• Prepare for an eventual return to negotiations, with low expectations for short-term breakthroughs.

• Enhance defense and deterrence capabilities and sanctions enforcement to both protect against North Korea’s growing threats and negotiate from a position of strength, if and when Pyongyang returns to dialogue.

• Communicate positions on humanitarian assistance and human rights as separate from denuclearization diplomacy.

Prepare for an eventual return to negotiations.

Devise roadmaps toward complete and verifiable denuclearization.

• In pursuit of the goal of denuclearization, parties should consider interim steps that reduce the threat and build confidence among distrustful counterparts in the negotiation.

• These interim steps could start with a missile (including long- and short-range options) and nuclear weapons test ban in return for partial sanctions lifting (with snapback clauses) and interim energy provision.

  • While reaching an agreement on a test ban will not be easy, this interim goal is more achievable than other possible measures, such as a freeze on fissile material production that would require North Korean cooperation for verification.

• Once a testing freeze is achieved, a separate but parallel political dialogue channel should be opened to address issues outside of the denuclearization negotiation, including mutual threat reduction, political normalization, the return of POW/MIA remains, and a peace regime.

• The denuclearization channel should focus on next steps after the freeze, including the phased, verified shutdown and eventual disablement and dismantlement of key fissile material and nuclear weapons production facilities. This would be followed by declaration of fissile material and warheads in preparation for disablement, dismantlement, and removal.

• A separate negotiation should be instituted that focuses on missile technology control and inspection of undeclared North Korean missile bases.

• The United States and South Korea should consider a Nunn-Lugar-type program for scientific talent in North Korea.

• The United States and South Korea should require China to carry its fair share of the costs associated with any energy assistance incorporated in a shutdown of North Korea’s programs and facilities, ensuring that China’s financial and reputational well-being are at stake with any North Korean noncompliance

Signal openness to diplomacy.

• The United States should appoint a full-time special representative for North Korea. Even in the absence of negotiations, the envoy could work to coordinate potential roadmaps for North Korea’s denuclearization among key stakeholders in Washington, Seoul, and Tokyo.

• The United States and South Korea should continue to express a willingness to engage with North Korea. This could involve sending joint communications from senior envoys indicating a readiness to talk without preconditions.

Enhance defense, deterrence, and sanctions enforcement.

Strengthen defense and deterrence.

• The United States and South Korea should resume joint military exercises to enhance military readiness. These have been suspended or downgraded as part of previous negotiations.

  • The allies should consider expansion of the scope and nature of exercises, particularly those elements that improve the extended deterrence commitment for dealing with a nuclear North Korea. These improvements need not be publicized.

  • The allies should not trade a cessation of military exercises for a reversible test ban by North Korea.

• The United States should support South Korea’s military improvements, including the “Kill Chain,” early deployment of Iron Dome, an additional Korean Terminal High Altitude Area Defense (THAAD) battery, directed energy possibilities, and upgraded ship-based defenses.

  • The United States should include South Korea in its efforts to develop an “all-in-one” sensor that would integrate listening, communicating, jamming, and injecting functions.

  • The United States should move South Korea to the top of the list for purchase of a THAAD battery, given the urgency of the North Korean missile threat.

  • The United States should also consider potentially allowing South Korea to station some of its assets on U.S. bases, such as allowing South Korea to acquire and deploy dual-capable fighters in Guam, if necessary.

• The United States and South Korea should update their wartime operation plans, establishing new military directives to incorporate broader conflict scenarios.

• U.S.-ROK space cooperation should be expanded in order to enhance reconnaissance capabilities to detect and deter North Korean threats.

• The allies should not under current circumstances redeploy U.S. tactical nuclear weapons to the Korean peninsula nor condone the acquisition of nuclear weapons by South Korea (the latter comports with the policy of the allied government).

  • Support for these policy options within South Korea is driven, in part, by doubts regarding the credibility of U.S. extended deterrence. This can be addressed through alternative policy initiatives that avoid the downsides of these options (detailed in the following section).

Enhance counter-missile strategy.

• The allies should develop a broad counter-missile strategy that focuses on detecting and defending against North Korean missiles and launchers, disrupting its capability networks, and destroying its launchers and missiles.

• As an element of this strategy, the allies should strengthen missile defense coordination. This is essential given North Korea’s advances in its missile defense evasion capabilities and the legacy technologies that the United States currently relies on to counter the North Korean ICBM threat to the homeland.

• The allies should work to harden potential targets of North Korean missile strikes in South Korea, including critical infrastructure and other facilities in the greater Seoul metropolitan area.

• The allies should also investigate new concepts of missile defense, such as boost-phase systems, in their nascent phases, which would help to overcome the limitations of current U.S. missile defense systems.

Increase trilateral defense cooperation.

• The United States, South Korea, and Japan should reinstate the Trilateral Consultation and Oversight Group as a regular channel of communication and policy coordination on North Korea.

• The three allies should consider additional forms of military cooperation to deter a nuclear North Korea, including information sharing, anti-submarine warfare, missile defense, contingency planning, and regular trilateral exercises to develop and demonstrate combined capabilities.

  • The three countries’ recent agreement to resume joint missile early warning exercises, which could include the interception of a dummy North Korean missile, is a step in the right direction.

• To improve transparency, South Korea and Japan should engage in trilateral briefings about their respective defense improvement plans as well as developments related to extended deterrence.

Bolster sanctions enforcement.

• The United States and South Korea, together with Japan, should lead efforts to enforce existing sanctions on North Korea, including deterring illegal ship-to-ship transfers by North Korea and pressuring countries to return North Korean laborers working overseas in violation of international sanctions.

• The allies should be ready to offer sanctions lifting but only for substantive and difficult-to-reverse steps on denuclearization by North Korea.

• The United States and South Korea must step up pressures on China and Russia to enforce UN Security Council Resolution (UNSCR) sanctions against North Korea, including trigger clauses in those resolutions.

• Should China and Russia not comply with UNSCRs, the United States should expand secondary sanctions against China and Russia.

Increase support for humanitarian assistance and human rights.

• The United States and South Korea should consider immediate humanitarian assistance to North Korea through the international aid community to help improve the conditions for North Korean citizens.

  • Covid-19 vaccines, cold-chain storage, personal protective equipment, and test kits are necessary to mitigate the current spread of Covid-19 inside of the country.

  • The border lockdown, which has been in place for 33 months, has generated the need for additional assistance in food and medicines.

• The United States should support the South Korean government’s proposal for a “green détente” dialogue with North Korea.

• The United States must appoint a special envoy for North Korean human rights.

• The United States and South Korea should jointly advocate for North Korean human rights by co-sponsoring North Korean human rights resolutions in the United Nations and taking every available opportunity to speak up on this issue there and at other fora.

  • The two governments should also support NGO initiatives to increase the North Korean population’s access to outside information and enforce the implementation of existing human rights-related sanctions.

Policy Recommendations on U.S. Extended Deterrence

The Present and Future of Extended Deterrence

The U.S. extended deterrence commitment to South Korea refers to Washington’s pledge to devote the full range of its military capabilities, including nuclear weapons, to deter and, if necessary, defeat an external attack on South Korea. It involves two central purposes: to deter North Korean aggression in all of its forms, and to prevent nuclear proliferation by providing South Korea with an alternative to developing its own nuclear weapons to meet its security needs.

This commitment has physical and psychological aspects that both affect its credibility. Acquiring and demonstrating the military capabilities the United States needs to protect South Korea from North Korean threats is critical but insufficient. For extended deterrence to be effective, North and South Korea must also believe that the United States is willing to use these capabilities to defend its allies — even if it means risking Washington, D.C., or New York to save Seoul or Tokyo. As such, extended deterrence requires consistent U.S. demonstrations and assurances of both capabilities and will.

North Korea’s increasing weapons capabilities, its threats to use nuclear weapons for offensive purposes, and the vulnerability of U.S. national missile defense interceptors to North Korean multiple independent re-entry vehicle technologies have led the South Koreans to question the credibility of U.S. extended deterrence in recent years. In general, doubts regarding the credibility of extended deterrence can be expected to grow whenever North Korea’s capability or will to attack South Korea or the U.S. homeland exceeds the United States’ (actual or perceived) capability or will to defend South Korea from an external attack.

Future developments could further heighten doubts regarding the credibility of U.S. extended deterrence. For instance, if a new U.S. administration comes to power that does not place alliances at the center of its regional strategy (similar to the Trump administration’s approach in questioning the need for U.S. troops in South Korea) or returns to a policy of strategic patience, questions about the will of the United States to uphold its extended deterrence commitments will proliferate.

China’s growing military capabilities also loom in the background of this picture. China’s military modernization efforts in recent decades have been a focus of U.S. regional policy writ large but not a target for U.S.-ROK deterrence policies on the Korean peninsula. This is because the perceived risk of China using its military to either invade South Korea directly or support a second North Korean invasion has been deemed to be low since the end of the Korean War. After all, an outbreak of militarized hostilities on the peninsula would significantly increase the chances of two destabilizing developments that Beijing seeks to avoid: U.S. troops mobilizing near the North Korea–China border and a severe humanitarian crisis on its doorstep. Even considering China’s increasingly unhelpful behavior with respect to North Korea since the start of the war in Ukraine, these general assumptions regarding China’s aversion to militarized hostilities on the Korean peninsula remain sound.

But this could change if China perceived that renewed conflict on the peninsula had a good chance of severing, rather than unifying, the alliance. This would decrease the likelihood of U.S. troops on its border and open new possibilities for China to increase its influence on the peninsula. These types of hypothetical scenarios are on the minds of South Koreans as they consider the possibility that future U.S. administrations could downgrade the importance of alliances, thereby increasing the chance that South Korea will be left to fend for itself against North Korea and China. The relevance of Chinese military capabilities for South Korea’s security has also increased in recent years in light of Beijing’s increasing tendency to view Seoul’s defensive postures vis-à-vis North Korea as directed at China, showcased in its actions to punish South Korea for the THAAD battery deployment in 2017. There is a strong possibility that Beijing will use similar logic to argue that any future U.S. moves to improve U.S. national missile defenses against North Korea are actually efforts to deter China, thereby injecting broader concerns about strategic stability into the picture. These scenarios — both hypothetical and real — point to the need to factor the evolving significance of China’s military capabilities for the Korean peninsula into discussions about the future of extended deterrence.

STRATEGIC PRINCIPLES

Efforts to strengthen U.S. extended deterrence should be guided by an acknowledgement of its dual purpose (deterrence and nonproliferation) and nature (physical and psychological), as well as a firm understanding of the conditions that have caused, or are likely to cause, South Koreans or others to question its credibility.

• The psychological question of how to build trust and belief in U.S. extended deterrence is a good place to start in devising new initiatives. After all, the issue that has perhaps the highest potential to divide the allies in the coming months — whether to redeploy U.S. tactical nuclear weapons on the peninsula — is driven more by psychological than by physical factors.

• Avoid policies that put the two purposes of extended deterrence into conflict, for instance, by advancing deterrence but setting back nonproliferation efforts.

• Ensure that policies designed to enhance credibility respond directly to the specific factors undermining credibility at that time and do not create new military dilemmas.

The psychological question of how to build trust and belief in U.S. extended deterrence is a good place to start in devising new initiatives.

New extended deterrence policies should not lose sight of the fact that the U.S.-ROK “community of fate” is and will remain at the heart of U.S. security commitments to South Korea.

• The “community of fate” refers to the 28,500 U.S. troops in South Korea that tie the country together with the United States strategically, ensuring that North Korea cannot use nuclear weapons or attack South Korea conventionally without killing Americans.

• This community of fate links events on the ground to the U.S. nuclear umbrella and makes it credible, thereby forming the core of extended deterrence.

• Anything the allies do to enhance extended deterrence should aim to build on the community of fate, not displace it.

SPECIFIC EXTENDED DETERRENCE POLICIES (PURSUANT TO THE PRINCIPLES)

Policies to strengthen U.S. extended deterrence should be pursued along six general tracks:

1. Public communications;

2. Joint planning and execution;

3. Trilateral discussions and operations;

4. U.S. military adjustments and improvements;

5. Pre-decisional groundwork to prepare for the possible future deployment of U.S. tactical nuclear weapons; and

6. Coordinating positions on China.

All of these efforts will help to bolster the psychological or physical aspects of extended deterrence, often simultaneously, by showcasing U.S. capabilities and will to uphold its commitments.

Public Communications

Provide reassurance and clarification on existing and new U.S. capabilities.

• The United States should continue to broadcast at the highest levels its commitment to provide extended deterrence to South Korea using “the full range of U.S. defense capabilities, including nuclear, conventional, and missile defense capabilities,” as President Biden did in the May 2022 U.S.-ROK Leaders’ Joint Statement.

• When referencing the “full range of U.S. defense capabilities,” the United States should emphasize that the U.S.-ROK “community of fate” — anchored in the presence of 28,500 U.S. troops on the peninsula — forms the core of extended deterrence, regardless of additional U.S. capabilities that may be introduced.

• Public communications should acknowledge quiet alliance conversations about the potential redeployment of U.S. tactical nuclear weapons and possible preliminary measures (see point 5 below) while stressing that the allies would not commit to deployment without careful consideration of the downsides.

Improve joint planning and execution.

• The allies should take a number of steps to improve joint planning and the execution of various aspects of extended deterrence, including:

  • Create a framework for joint nuclear planning. This would be similar to a NATO planning group for nuclear weapons use, with planning conducted bilaterally and trilaterally (with Japan) and control remaining in the hands of the United States. Experts see this as one of the most critical steps to developing stronger bonds of trust between the allies in the current environment.

  • Sustain practices such as sending a senior South Korean liaison officer to U.S. Strategic Command. This practice began a few years ago and gives South Korea a presence inside the key headquarters that plans for and executes any use of nuclear weapons.

  • Reactivate the high-level Extended Deterrence Strategy and Consultation Group (EDSCG) as soon as possible. This will help in generating combined assessments of the risk of strategic deterrence failure and in setting policies that mobilize specific responses to these assessments.

  • Streamline the protocols for direct Space-Based Infrared System access to South Korea in addition to the geographic commanders, as the United States does for Israel and Japan.

  • Revive track 1.5 unclassified dialogues in parallel with EDSCG meetings to incorporate a broader range of perspectives and potentially involve participants from Japan and other strategic partners, such as Australia, the United Kingdom, and France.

  • Potentially explore the prospects for multilateral nuclear umbrella guarantees by engaging other like-minded partners, such as the United Kingdom and France.

Expand trilateral operations and discussions.

• The allies should welcome new opportunities to bring together U.S.-Japan and U.S.-South Korea discussions and exercises related to extended deterrence.

  • Even though the state of the debate in Japan on options for strengthening extended deterrence is in a different place than in South Korea, the two countries should take advantage of the fact that they share concerns about the credibility of extended deterrence.

• Supplement the two extended deterrence dialogues with South Korea and Japan with a track 1.5 trilateral strategic exchange in order to stay informed about developments in each country and identify opportunities for coordination.

• The United States, South Korea, and Japan should look for ways to trilateralize operational activity that involves strategic assets, such as along the lines of Blue Lightning missions.

• The allies should consider undertaking a nuclear planning exercise trilaterally.

Pursue U.S. military adjustments and improvements.

• The United States should consider changing its regional strategic and nuclear posture to allow for more robust and constant demonstrations of its capabilities.

  • Specifically, this could entail the continuous presence in the region of either U.S. submarines equipped with nuclear cruise missiles or strategic bombers or investing in infrastructure in South Korea to receive U.S. dual-capable aircraft.

  • Regarding the relative value of different strategic assets, relying primarily on sea-based systems makes the most sense from an operational standpoint, while rotational deployments of dual-capable aircraft would have more political reassurance value than operational military significance.

• The United States should improve its national missile defense capabilities vis-à-vis North Korea, including through accelerating its plans to deploy 20 additional interceptors equipped with Next Generation Interceptor technology, currently slated for 2028, and investing in boost-phase missile defense technologies.

  • Both of these initiatives would enhance the United States’ capacity to deflect a North Korean attack on the U.S. homeland with nuclear-tipped missiles (deterrence by denial) while avoiding an unviable “numbers game” — involving a scramble to produce enough U.S. interceptors to match increasing numbers of North Korean launchers — that would ensue from continued reliance on old technologies.

• The United States should continue its nuclear modernization efforts, including the Long Range Stand Off Weapon and B-21, and should not include the “no first use” or “sole purpose” clause in the upcoming Nuclear Posture Review.

  • The United States should also restore funds for and continue pursuing its nuclear sea-launched cruise missile (SLCM-N) program.

  • These efforts would help to reassure South Koreans — and convince North Koreans — of U.S. capabilities to fight and win a war against North Korea, thereby upholding deterrence by punishment.

Lay pre-decisional groundwork for possible redeployment of U.S. low-yield nuclear weapons.

• The allies should consider tabletop planning exercises for the possible redeployment of U.S. nuclear weapons to South Korea. This planning should be explicitly pre-decisional. The timeline and scope of weapons, such as low-yield nuclear SLCMs or gravity bombs, should be left deliberately ambiguous. Decisionmaking would be calibrated to shifts in the security environment and the North Korean threat level.

• Such planning exercises could entail cumulative phases, including:

  1. Studies of the environmental impacts of redeployment;

  2. Mapping of possible locations for facilities for storage;

  3. Joint training on nuclear safety and security, including storage security, incident response, and recovery operations;

  4. Certifying Korea-based U.S. F-16 units or F-35 replacements for combined exercises and nuclear missions; and

  5. More committal physical steps toward redeployment, such as building storage facilities — a process that could take a few years to complete.

  The committal, physical steps would only be pursued if North Korean threat levels continued to escalate after other options to strengthen extended deterrence were exhausted (e.g., if North Korea intensifies its provocations even after the United States deploys nuclear SLCMs to the region, creates a joint nuclear planning framework, and ramps up its nuclear modernization efforts).

• The redeployment of tactical nuclear weapons could heighten tensions on the peninsula despite its intended deterrent effect. This type of pre-decisional preparatory framework would signal commitment to the allies and resolve to North Korea while not yet crossing the proliferation threshold. It would also create new pressure on North Korea to stop ratcheting up threat levels if it does not want to see U.S. tactical nuclear weapons return to the peninsula.

Coordinate positions on China.

• The allies should establish a bilateral consultative mechanism to share assessments of the implications of China’s military capabilities for the Korean peninsula and coordinate potential responses.

• The allies should develop plans to jointly respond to Chinese pressure tactics aiming to derail allied deterrence initiatives directed toward North Korea.

• The United States should respond to any Chinese complaints about Washington’s efforts to strengthen its missile defenses against North Korea by highlighting the degree to which the U.S. homeland missile defense system is neither intended to nor capable of defending against ICBM capabilities as large and sophisticated as China’s.

• If China returns to a more helpful posture on North Korea issues, the United States and South Korea should consider incorporating Beijing into multilateral talks to secure China’s responsibility as a major stakeholder in North Korea’s denuclearization.

North Korea policy is famously known as the “land of lousy options.” Currently, North Korea’s nuclear weapons and ballistic missile programs look unstoppable. Decades of failed denuclearization diplomacy, however, cannot deter the allies from seeking new avenues of engagement with the modest goal of slowing down the program’s growth. Failing that objective, the United States must be cognizant that contingency planning, enhanced military readiness, and strengthened extended deterrence measures with South Korea and Japan serve to make U.S. alliances in Asia stronger, which in turn impose costs on North Korea for its proliferation behavior.

John J. Hamre, President and CEO, and Langone Chair in American Leadership, CSIS.

Joseph S. Nye, Jr., Distinguished Service Professor, Harvard University; Trustee, CSIS.

Victor D. Cha, Senior Vice President for Asia and Korea Chair, CSIS; Vice Dean for Faculty and Graduate Affairs and D.S. Song-KF Professor of Government, Georgetown University; Former Director for Asian Affairs, National Security Council.

Katrin F. Katz, Adjunct Fellow (Non-resident), CSIS Korea Chair; Former Director of Korea, Japan and Oceanic Affairs, National Security Council.