Toward Mutual Reassurance on the Korean Peninsula and in Northeast Asia

This report synthesizes the findings of the 2025 Toda Research Cluster on Reassurance on the Korean Peninsula, bringing together theoretical, national, and policy perspectives from the United States, South Korea, Japan, China, and Russia. In the context of rising great-power rivalry and the consolidation of competing blocs, the contributors argue that deterrence alone cannot sustain stability. Drawing on insights from the five core papers, the report identifies mutual reassurance as an essential complement to deterrence. The analysis highlights converging recommendations for arms control-based risk reduction, revitalized inter-Korean and multilateral channels, calibrated adjustments to alliance posture, and leadership-level credibility. While acknowledging the long-term goal of denuclearization, the report emphasizes pragmatic pathways for near-term stabilization, offering a structured framework for building a durable reassurance architecture in Northeast Asia.

 

Contents

• Abstract
• Introduction
• Background and objectives of the Toda research cluster
• Theoretical foundations: Reassurance in the deterrence–compellence continuum
• US–DPRK–ROK Track: Reassurance through stable coexistence
• Japan’s perspective: Coordinated reassurance and the phased freeze
• China’s perspective: Responsible reassurance in a fragmenting region
• Leadership diplomacy and the new Cold War context
• Comparative analysis: Convergences and divergences
• Policy implications and pathways forward
• Conclusion

Abstract

This report synthesizes the findings of the 2025 Toda Research Cluster on Reassurance on the Korean Peninsula, bringing together theoretical, national, and policy perspectives from the United States, South Korea, Japan, China, and Russia. In the context of rising great-power rivalry and the consolidation of competing blocs, the contributors argue that deterrence alone cannot sustain stability. Drawing on insights from the five core papers, the report identifies mutual reassurance—defined as credible actions that reduce misperception, signal restraint, and institutionalize communication—as an essential complement to deterrence. The analysis highlights converging recommendations for arms control-based risk reduction, revitalized inter-Korean and multilateral channels, calibrated adjustments to alliance posture, and leadership-level credibility. While acknowledging the long-term goal of denuclearization, the report emphasizes pragmatic pathways for near-term stabilization, offering a structured framework for building a durable reassurance architecture in Northeast Asia.

Introduction

The Korean Peninsula remains one of the most heavily militarized and politically volatile regions in the international system. More than seventy years after the signing of the armistice, the Korean War has never been formally concluded, and the peninsula continues to function under a fragile and uneasy balance of power.
Military confrontation has been deterred, but it has not been transformed into sustainable peace. Periodic crises, nuclear and missile tests, and episodes of coercive signalling have entrenched a pattern in which deterrence is constantly reaffirmed but mutual confidence is never built.

Against this backdrop, the Toda Peace Institute launched, in 2025, the Research Cluster on Reassurance on the Korean Peninsula. The cluster’s central question is whether it is possible to move beyond an almost exclusive reliance on deterrence and sanctions and to design concrete mechanisms of mutual reassurance among the parties directly and indirectly involved in the Korean conflict. Reassurance is understood here not as a naïve appeal to goodwill, but as a set of strategic actions—verbal commitments, institutional arrangements, and military postures—that reduce misperceptions, signal restraint, and create channels for managing crises before they escalate.

The October 2025 Tokyo workshop brought together scholars and former policymakers from South Korea, Japan, China, the United States, and the media community. The core analytical contributions came from Frank Aum, Junya Nishino, Dong Wang, Reid B. C. Pauly, and Jae-Yoon Jung. Their papers approach the same problem from different angles: theoretical, American, Japanese, Chinese, and journalistic-policy perspectives.
Collectively, they grapple with an environment marked by (1) deepening US–China strategic competition, (2) visible consolidation of two regional blocs—US–Japan–ROK versus China–DPRK–Russia, and (3) significant institutional erosion in inter-Korean and multilateral diplomacy.

This conference report synthesizes the main arguments of these papers and one and a half day of discussion, identifies their common themes and differences, and draws out the policy implications for the Toda Peace Institute’s ongoing work. It proceeds in four steps. First, it introduces the background and objectives of the research cluster. Second, it summarizes and compares the individual papers, starting with the theoretical foundations and then moving through the major national perspectives. Third, it analyses the convergences and divergences among the authors, especially regarding the relationship between deterrence, compellence, and reassurance. Finally, it offers a set of policy-relevant conclusions and suggests avenues for future research and advocacy.

The overarching finding is clear: mutual reassurance is not a luxury but a strategic necessity. In a context where complete denuclearization is no longer a realistic short-term prospect, reassurance is the main available tool to stabilize deterrence, reduce miscalculation, and create political space for future progress.

Background and objectives of the Toda research cluster

The Toda Research Cluster on Reassurance on the Korean Peninsula was established with the explicit goal of shifting the policy debate away from a narrow focus on deterrence and coercive pressure. The starting premise is that while deterrence is necessary, it is not sufficient for durable stability. Threats alone cannot sustain peace indefinitely; they must be supplemented by credible assurances that adversaries will not be punished if they refrain from aggression or, at minimum, that their basic security will not be undermined if they comply with certain rules.

The cluster was tasked with two main objectives. The first was analytical: to clarify what ‘reassurance’ means in theory and practice, and how it differs from related concepts such as appeasement, inducement, and mere ‘confidence-building’. The second objective was policy-oriented: to identify concrete steps that the parties to the Korean conflict—North Korea, South Korea, the United States, China, Japan, and Russia—could realistically take in the current environment to reduce tensions and manage conflict risks.

Participants agreed that the peninsula’s instability is driven by at least two structural trends. The first is the emergence of bloc politics in Northeast Asia. The deepening trilateral cooperation among the United States, Japan, and the Republic of Korea—highlighted by the Camp David summit and subsequent joint military exercises—has been mirrored by closer political, military, and symbolic coordination among China, North Korea, and Russia. The joint appearance of Xi Jinping, Vladimir Putin, and Kim Jong-un at the September 2025 military parade in Beijing has become a powerful image of this emerging alignment. In such an environment, each side tends to reinterpret the other’s defensive measures as offensive threats, thereby intensifying the classic security dilemma.

The second trend is the erosion of institutionalized dialogue. The inter-Korean liaison office has been destroyed; military hotlines have been cut and restored only intermittently; and the Six-Party Talks have long since ceased to operate as a platform for negotiation. At the same time, new mechanisms such as the Nuclear Consultative Group (NCG) between Seoul and Washington have reinforced deterrence, but without embedding corresponding channels for direct risk reduction with Pyongyang.

The research cluster therefore treats reassurance not as an abstract normative aspiration but as a pragmatic risk-management strategy. It asks what kinds of assurances could realistically be offered and received, under what conditions they might be credible, and how they can be institutionalized in ways that constrain future escalation. It is from this vantage point that the individual papers should be read.

Theoretical foundations: Reassurance in the deterrence–compellence continuum

Reid B. C. Pauly’s paper provides the conceptual backbone for the cluster’s work. Drawing on his book The Art of Coercion and recent articles, Pauly clarifies how assurance functions within the broader logic of coercion, and why it is central to any effort to stabilize the Korean Peninsula.

Pauly distinguishes among three analytically distinct forms of assurance. First, reassurance of adversaries is an attempt to communicate “I mean you no harm” or, more precisely, “I will not attack you as long as you refrain from certain actions.” Reassurance of this type is designed to mitigate the security dilemma by signalling defensive intentions and limiting the perceived scope of one’s ambitions. Second, coercive assurance operates inside a coercive relationship and effectively says, “If you comply with my demands, I will not punish you further.” This is the essence of Thomas Schelling’s notion of assurance in coercion. Third, ally reassurance consists of promises to defend partners and to uphold extended deterrence commitments.

On the Korean Peninsula, all three forms are simultaneously in play according to the discussion by all participants. The United States and South Korea attempt to reassure each other and Japan that the alliance remains credible, while at the same time signalling to North Korea that they will not seek regime change if Pyongyang refrains from aggression. Concurrently, Washington and Seoul have to convey to Pyongyang that compliance with agreements—whether nuclear or conventional—will actually produce security and economic benefits rather than inviting new demands.

Pauly emphasizes the ‘assurance dilemma’: in order to succeed, coercive diplomacy must persuade the target both that threats are real and that compliance will genuinely avert or alleviate punishment. If demands are too expansive or if leaders signal that they will seek to punish the target regardless of its behaviour, assurances lose credibility. In such circumstances, the target is likely to believe that it is “damned if it does and damned if it doesn’t,” and will therefore resist or hedge rather than comply.

From this perspective, Pauly argues that the long-standing insistence on complete, verifiable, and irreversible denuclearization (CVID) as the starting point of negotiations has inadvertently undercut deterrence stability, which some of the participants supported. Denuclearization is a compellent goal: it aims to change the status quo by forcing North Korea to relinquish capabilities that it views as central to its survival. When coupled with rhetoric about ‘the end of the regime’, such demands signal to Pyongyang that its nuclear surrender might invite its eventual destruction, thus undermining any assurance that restraint will yield safety.

He further notes that signalling practices matter. Costly signals of restraint—such as scaling back joint exercises or publicly ruling out regime change—can enhance reassurance by showing that a state is willing to incur domestic or alliance costs to avoid escalation. By contrast, military exercises that highlight leadership-targeting capabilities or doctrines emphasizing pre-emptive strikes can be stabilizing for deterrence only if they are carefully calibrated; they risk creating ‘use-it-or-lose-it’ incentives for the adversary’s nuclear forces.

Pauly concludes that any strategy for stabilization must re-balance deterrence and reassurance. This does not mean abandoning deterrence, but rather embedding it in a framework that clarifies red lines, avoids maximalist objectives in the short term, and offers credible pathways by which the adversary can improve its security through cooperation. His theoretical insights set the stage for the more concrete proposals advanced by the other authors.

US–DPRK–ROK Track: Reassurance through stable coexistence

Frank Aum’s paper, “Building Mutual Reassurance on the Korean Peninsula Through Stable Coexistence,” takes Pauly’s theoretical framework and translates it into a detailed policy agenda. Aum begins from a stark assessment: complete denuclearization of North Korea is not attainable in the near term given Pyongyang’s current doctrine, capabilities, and domestic legitimacy needs. Yet he argues that this does not mean diplomacy is futile. Instead, he proposes a Stable Coexistence Framework that aims to manage, rather than resolve, the underlying conflict.

The framework rests on five mutually reinforcing themes:

1. Stable coexistence with respect for sovereignty

Aum suggests that the United States and North Korea should negotiate a time-bound political understanding that reinforces mutual sovereignty and non-interference. This could include a symbolic end-of-war declaration that formally acknowledges that the Korean War has ended, coupled with non-aggression language and a commitment to work toward normalization of relations. Such steps would not recognize North Korea as a legitimate nuclear-weapon state, but they would address Pyongyang’s core concern that Washington is seeking regime change.

2. Arms control without nuclear recognition

Recognizing the improbability of immediate denuclearization, Aum proposes an arms control–focused approach that seeks to reduce risks and cap capabilities. Possible measures include a moratorium on nuclear and long-range missile tests; shutdown of key facilities such as Yongbyon; a pledge not to export nuclear materials, technology, or delivery systems; and limits on forward-deployed or highly destabilizing systems such as hypersonic glide vehicles and MIRVed missiles. The emphasis is on tangible, verifiable steps that reduce the likelihood of crisis escalation without formally legitimizing North Korea’s nuclear status.

3. Front-line guardrails

The 2018 Comprehensive Military Agreement (CMA) between the two Koreas demonstrated that carefully designed confidence-building measures—such as no-fly and no-sail zones, withdrawal of guard posts from the Demilitarized Zone (DMZ), and demilitarization of the Joint Security Area—can significantly lower the risk of accidental clashes. Aum calls for revitalizing and updating these provisions, as well as creating cyber incident hotlines and pre-notification regimes for major exercises. These ‘guardrails’ are key instruments of reassurance because they reduce the danger that routine military activity will be misread as preparation for attack.

4. Humanitarian, educational, and societal contact

Aum argues that mutually agreed ‘white-list’ projects—limited, low-risk cooperation in areas such as public health, disaster management, agriculture, and family reunions—can build habits of interaction while respecting Pyongyang’s desire to control information flows. He recommends the use of escrow mechanisms and vetted implementing organizations to prevent diversion of funds or politicization of humanitarian aid. These initiatives are not primarily about changing North Korea’s political system; they are meant to reduce human suffering and gradually create constituencies for continued engagement.

5. Regional scaffolding

Finally, Aum insists that any peninsular reassurance framework must be embedded in a regional security architecture. He proposes a Northeast Asia Risk Reduction Forum at the Track 1/1.5 level, involving the two Koreas, the United States, China, Japan, and Russia. The forum would not necessarily replace the Six-Party Talks, but it would serve as a practical venue for discussing maritime and aerial deconfliction, test notification protocols, crisis communication, and export control enforcement.

Taken together, these five pillars amount to an ‘operating system’ for managing rivalry. Participants strongly shared that this is not a settlement: it neither resolves historical grievances nor dismantles North Korea’s nuclear arsenal. Instead, it seeks to narrow the pathways to conflicts and keep open the possibility of more ambitious goals in the future. All agreed that we may need both modesty in defining immediate aims and audacity (or ambition) in attempting to reframe the logic of engagement.

Japan’s perspective: Coordinated reassurance and the phased freeze

Junya Nishino’s paper, “Building Mutual Reassurance on the Korean Peninsula: Coordinating ROK, Japan, and US Approaches to North Korea’s Nuclear Challenge,” introduces the critical Japanese perspective. He begins by emphasizing that the North Korean nuclear issue is not a distant or abstract threat for Japan, but an immediate existential concern. North Korean ballistic missiles can strike Japanese territory with little warning, and Pyongyang’s evolving doctrine has explicitly framed Japan as a hostile state and potential target.

From this vantage point, Nishino argues that any reassurance policy toward North Korea must be embedded in close trilateral coordination among Seoul, Tokyo, and Washington. Reassurance that neglects Japan’s security interests would be politically unsustainable and could actually weaken alliance cohesion.

In line with public proposals from South Korean President Lee Jae-myung, Nishino proposes a three-stage roadmap for dealing with North Korea’s nuclear and missile programs:

1. Freeze

In the first stage, the priority would be to freeze further qualitative and quantitative advances in North Korea’s nuclear and missile capabilities. This would entail halting nuclear tests, ICBM and longer-range missile launches, and the production of fissile material, under some form of monitoring. Precise definitions—what is included in the freeze, how it is verified, and what constitutes a violation—would need to be agreed jointly by the ROK, Japan, and the United States.

2. Reduction

In a second phase, once basic trust and verification mechanisms have been established, the goal would shift to reducing stockpiles and dismantling specific facilities or systems. This might involve partial dismantlement of warheads, conversion of sites, or long-term storage under international supervision.

3. Denuclearization

Only in a final phase would complete denuclearization be pursued. Nishino insists that this objective should not be abandoned, but he acknowledges that it is a long-term aspiration that requires interim stabilization through the first two stages.

Beyond this roadmap, Nishino underscores three themes. First, he highlights the necessity of inter-Korean dialogue infrastructure, particularly the South–North Joint Military Committee mandated by the 1991 Basic Agreement and the 2018 CMA but never operationalized. Without such mechanisms, he argues, even well-intentioned policies are vulnerable to derailment during crises.

Second, he stresses the importance of domestic consensus within South Korea and Japan. The collapse of the 2018–2019 peace process, in his view, was due partly to political polarization and insufficient public understanding of the trade-offs involved. For reassurance strategies to endure, they must be anchored in a broad base of societal and parliamentary support.

Third, Nishino insists that Japan’s specific concerns—including the long-standing abduction issue—must be addressed. Without credible steps from Pyongyang on the fate of abducted Japanese citizens, it will be politically difficult for any Japanese government to endorse major economic assistance or normalization. Reassurance, therefore, is not purely a military or strategic notion; it has a human and moral dimension that cannot be ignored.

Some of the participants raised their concerns that the abduction issue might entangle with the assurance postures. In terms of the policy priorities, the participants argue that the abduction issue will not help Japan’s strategic calculus but constrain the strategic manoeuvrability dealing with North Korea.

All in all, Nishino’s analysis converges with Aum’s in its emphasis on realism and sequencing, but it adds the crucial insight that reassurance on the Korean Peninsula cannot succeed if Japan is treated as a peripheral player.

China’s perspective: Responsible reassurance in a fragmenting region

Wang’s paper, “From China’s Responsible Reassurance to Mutual Reassurance in Northeast Asia,” situates the Korean Peninsula problem within the broader landscape of US–China strategic competition and regional bloc formation. He argues that Northeast Asia has entered a period of heightened structural instability, marked by the consolidation of the US–Japan–ROK bloc on one side and a China–DPRK–Russia grouping on the other. Historical grievances, power transitions, and leadership changes—all compounded by the return of Donald Trump to the White House—have contributed to a hardening of positions.

Wang introduces the concept of ‘responsible reassurance’ as a guiding principle for China’s regional policy. He contends that Beijing has an interest in preventing large-scale conflict on the Korean Peninsula, both to safeguard its own security and to preserve an environment conducive to economic development.
Responsible reassurance, in his usage, means exercising strategic restraint, clearly signalling red lines, and actively participating in mechanisms that reduce the risk of miscalculation.

He outlines four pillars of a Chinese strategy conducive to mutual reassurance:

1. Stabilizing US–China relations

Wang argues that the single most important variable for Northeast Asian security is the trajectory of US–China relations. While competition is inevitable, he calls for mechanisms that keep it bounded, including crisis hotlines, military-to-military talks, and regular summits that reaffirm mutual respect for each other’s core interests.

2. Managing relations with Japan and South Korea

He recommends that China continue to pursue trilateral cooperation with Japan and the ROK in areas such as trade, environmental protection, and pandemic response, even while disagreements persist over security and history. This ‘compartmentalization’ can help prevent tensions from spilling over into broader confrontation.

3. Preventing conflict on the Korean Peninsula

Beijing, in Wang’s view, should oppose any attempts—by Pyongyang, Washington, or others—to change the status quo through force. He notes that China’s recent high-level engagement with North Korea, including visits and participation in commemorative events, should be used not only to signal solidarity but also to encourage restraint.

4. Encouraging inter-Korean dialogue.

Finally, Wang suggests that China can play a useful role in nudging North Korea toward reopening channels with South Korea, particularly if Seoul maintains a policy of non-hostility and respect for the North’s political system.

Wang’s reading of the Trump 2.0 era is cautiously optimistic from a Chinese perspective. He expects a measure of US strategic retrenchment, with more burden placed on allies to manage their own security. This may provide space, he argues, for regional actors—including China—to exercise greater agency and to shape a more inclusive, multipolar order in Northeast Asia. His analysis adds a crucial regional layer to the cluster: reassurance on the peninsula cannot be isolated from the broader task of managing great-power rivalry.

Leadership diplomacy and the new Cold War context

Jae-Yoon Jung’s contribution brings a journalist’s eye for detail and narrative to the discussion. Her paper, “How Two Koreas, Along with China, Japan, the US, and Russia, Can Reassure One Another and Reduce Conflict Risks on the Peninsula,” begins with the powerful image of the September 3, 2025 parade in Beijing, marking the eightieth anniversary of victory in World War II, where Xi, Putin, and Kim appeared together. Jung interprets this event as a visual declaration of a new Cold War in which the Korean Peninsula lies at the centre of competing blocs.

Within this context, Jung focuses on the evolving dynamics of the US–ROK alliance under President Lee Jae-myung and President Donald Trump. He highlights the contrast between Trump’s role as a potential ‘peacemaker’, who claims personal rapport with Kim Jong-un, and Lee’s self-ascribed role as ‘pacemaker’, whose emphasis is on creating conditions for US–DPRK dialogue rather than monopolizing the diplomatic spotlight. Jung notes that while Pyongyang has responded quickly to some of Lee’s conciliatory gestures—such as the suspension of loudspeaker broadcasts—it has continued to disparage Seoul publicly and to insist that Washington is its sole relevant counterpart.

Jung makes several practical observations and recommendations:

• First, Jung argues that ‘complete denuclearization’ should not be placed at the front of the negotiating agenda in renewed talks. Rather, the focus should be on achievable steps such as test moratoria, partial sanctions relief, and limitations on joint military exercises near North Korea.
• Second, Jung emphasizes the importance of rebuilding a regular US–DPRK communication channel, whether through formal diplomatic missions or trusted intermediaries. The absence of such channels in 2019 contributed to the collapse of the Hanoi summit and the subsequent diplomatic freeze.
• Third, Jung explores how the modernization of the US–ROK alliance could be interpreted either as a threat or as a reassurance measure, depending on how it is framed and implemented. If modernization is pursued in a way that markedly enhances capabilities for operations beyond the peninsula—for example, emphasizing ‘strategic flexibility’ of US Forces Korea—it may alarm both Pyongyang and Beijing. If, however, modernization is framed as a means of stabilizing deterrence on the peninsula and accompanied by restraint in exercises and deployments, it could contribute to reassurance.
• Fourth, Jung underscores the potential importance of Track 2 or semi-official dialogues with Russia, given Moscow’s deepening relationship with Pyongyang. While the war in Ukraine and Western sanctions constrain formal engagement, Jung suggests that South Korea and Japan could use unofficial channels to explore Russian views on the peninsula and identify possible areas of overlapping interest, such as energy or transportation projects.

Jung emphasized the politics of leadership and perception. Reassurance is not only about treaties and institutions but also about how leaders communicate with one another and with their domestic audiences. The tone of summitry, the sequencing of concessions, and the management of expectations are all crucial for sustaining any new diplomatic opening.

Comparative analysis: Convergences and divergences

Taken together, the five core papers reveal a notable degree of consensus on the broad direction of policy, even as they differ on emphasis and detail.

On the side of convergence, four points stand out:

Rejection of denuclearization-first diplomacy
All authors recognize that insisting on immediate, complete denuclearization as a precondition for engagement is not realistic under current circumstances. Denuclearization remains a long-term aim for most, but the short- and medium-term focus must shift to arms control, risk reduction, and stabilization.

Complementarity of deterrence and reassurance
There is agreement that reassurance should not replace deterrence; rather, it should be designed to stabilize and refine deterrence. A purely deterrence-centric approach risks creating either an arms race or an accident-prone stalemate. When combined with credible assurances and clear signalling, however, deterrence can be made more predictable and less escalatory.

Centrality of institutionalized communication
All authors call for new or revitalized mechanisms: inter-Korean military committees, liaison offices, hotlines, risk reduction forums, and multilateral dialogues. These are seen as the minimal architecture for reassurance in a region where misunderstandings can have catastrophic consequences.

Recognition of Trump 2.0 as a structural variable
Whether they view this positively or negatively, the authors assume that Trump’s second term introduces both risks—because of unpredictability and transactional tendencies—and opportunities, given his personal relationship with Kim Jong-un and interest in dramatic diplomatic gestures. This reinforces the need for coordination among allies and careful design of any new engagement.

On the side of divergence, several differences emerge:

Primary agent and locus of change
Aum and Jung place particular weight on the U.S.–DPRK channel as the decisive arena where reassurance must be built. Nishino and Wang, by contrast, emphasize the importance of trilateral and regional frameworks, arguing that peninsular stability cannot be divorced from abroader Northeast Asian order. Pauly, meanwhile, is less concerned with the specific arena and more with the logic of credible communication in any setting.

Role of China
For Wang, China is a central and constructive actor whose policy choices will largely determine whether the region moves toward confrontation or cooperation. The other papers treat China more as a necessary stakeholder and source of leverage over Pyongyang than as the primary driver of reassurance.

Alliance posture
Nishino is most explicit in outlining the need to preserve and even strengthen allied deterrence capabilities while exploring reassurance. Aum and Jung, while not opposing deterrence, advocate more visible adjustments in exercises and force posture to reassure Pyongyang. Pauly warns that some forms of signalling—especially those highlighting first-strike ability—may be counterproductive for assurance.

Temporal horizon
Pauly’s analysis is oriented toward the long-term stability of coercive relationships. Aum and Jung are focused on the near- and medium-term imperative to avert crises and reopen channels. Nishino and Wang occupy an intermediate position, looking at how policies in the next few years will shape the region’s trajectory over a decade or more.

These differences do not amount to fundamental disagreement. Rather, they reflect the distinct vantage points—theoretical, national, and professional—from which the authors approach a shared problem. For the purposes of the Toda research cluster, this diversity of perspectives is an asset: it helps identify the range of feasible tools and highlights the need for multi-level reassurance, from bilateral to regional.

Policy implications and pathways forward

The comparative analysis suggests several policy implications that can guide both the Toda Peace Institute’s future work and the broader policy community.

First, reassurance should be pursued as a structured strategy, not as ad hoc gestures. The cluster’s work points to a sequence: initial stabilizing moves (e.g., moratoria and communication channels), followed by institutionalization (e.g., risk reduction fora and joint committees), and, only after a sustained period of stability, consideration of more ambitious political changes. This sequencing logic mirrors the freeze–reduction–denuclearization roadmap and is consistent with the concept of stable coexistence.

Second, there is a strong case for designing a Northeast Asia Risk Reduction Forum, as proposed by Aum and broadly compatible with Wang’s regional vision. Such a forum could begin with modest, technical agendas—notification of missile tests, standardization of NOTAM/NOTMAR procedures, maritime incidents at sea, and cyber incident reporting—but over time develop into a staple institution akin to the OSCE’s risk reduction mechanisms in Europe.

Third, the revitalization of inter-Korean mechanisms is essential. Regardless of the state of US–DPRK relations, the two Koreas share a highly militarized border and face daily risks of miscalculation.
Operationalizing the Joint Military Committee, restoring hotlines, and implementing updated buffer zones around the DMZ would directly serve reassurance objectives. Even if political dialogue remains limited, technical channels can lower tensions.

Fourth, the cluster’s findings underscore the need to rebalance the goals of denuclearization and stability. Denuclearization should remain the long-run objective of the international community, but equating progress solely with steps toward that objective can unintentionally make the peninsula less safe. Policy should recognize that partial arms control measures, confidence-building steps, and economic or humanitarian cooperation can be valuable in their own right as contributions to risk reduction.

Fifth, the work highlights the importance of domestic consensus and allied coordination. Reassurance strategies that are perceived domestically as naïve, unilateral, or insufficiently linked to national security concerns are unlikely to endure. This is particularly evident in Nishino’s emphasis on Japanese domestic politics and in the memory of domestic debates in South Korea around the 2018–2019 peace process.
Transparent communication with publics, consultation with legislatures, and alignment among allies are therefore crucial.

Sixth, the cluster’s analysis suggests that the Trump–Lee–Kim triangle will remain a central arena in which reassurance is either advanced or undermined. Given the personalities and preferences involved, there is both danger and opportunity. The Toda Peace Institute and other Track 2 actors may be able to play a constructive role in generating ideas, proposing confidence-building measures, and keeping channels open during times of official stalemate.

Conclusion

The 2025 Toda Research Cluster on Reassurance on the Korean Peninsula has demonstrated that mutual reassurance is both theoretically grounded and practically necessary in today’s Northeast Asia. Far from being a soft or idealistic notion, reassurance emerges from these papers as a hard-headed strategy for managing deep and enduring conflicts in ways that lower the risk of catastrophe.

The cluster’s participants do not deny the reality of power politics, nor do they underestimate the challenges posed by North Korea’s nuclear arsenal, domestic politics in each country, or great-power rivalry. What they collectively argue is that an exclusive reliance on deterrence and sanctions—especially when coupled with maximalist demands—will eventually drive the region toward either uncontrolled arms racing or crisis escalation. By contrast, a carefully designed mix of deterrence, arms control, and reassurance offers a more promising path: one that narrows the space for miscalculation, increases predictability, and preserves room for future political transformation.

For the Toda Peace Institute, the next step is to translate these analytical insights into concrete policy engagement. This might include scenario workshops with officials and experts, simulations of crisis-management mechanisms, or the drafting of model agreements for specific guardrails and communication protocols. It may also involve outreach to civil society, parliaments, and media to foster a broader understanding of why reassurance is not a concession to an adversary, but an investment in shared survival.

Mutual reassurance will not, by itself, resolve historical grievances or ideological divides. It will not immediately eliminate nuclear weapons from the Korean Peninsula. But it can help ensure that those weapons are never used, that crises are managed rather than allowed to spiral, and that the peoples of Northeast Asia are spared the horrors of another major war. In an age of renewed great-power rivalry and accelerating technological change, that alone would be a significant achievement—and one worth organizing policy around.

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