From Deterrence to Cooperative Security on the Korean Peninsula

ABSTRACT The 2018 US-DPRK Singapore Summit introduced a new model to guide resolution of long-standing disputes on the Korean Peninsula: a “lasting and stable peace regime” could be created simultaneously with the “complete denuclearization of the Korean Peninsula”. This model established a continuum of objectives and milestone that extends as far as creation of a nuclear-weapon-free zone in the region. An overlooked but critical obstacle to progress toward those objectives is the need to diminish the role of deterrence in inter-Korean affairs. Cooperative security, both as process and destination, is a useful concept for guiding the shift away from deterrence. Developing cooperative security necessitates deeper efforts than assumed in a peace regime to reduce aggregated offensive military capability. Beyond facilitation by the United States and China, the two Koreas have considerable agency to implement steps that alter their conventional military force balance and postures. Cooperative security can also help reduce the salience of nuclear deterrence on the Korean Peninsula by creating a conflict escalation firebreak, which can mitigate the risk that small-scale DPRK “tactical provocations” lead to major war, or even use of nuclear weapons. Inter-Korean initiatives are a critical complement to multiparty work on denuclearization and a peace regime, yet face several constraints from big power interests. Furthermore, pursuit of cooperative security is in basic tension with unification as the dominant framework for inter-Korean relations, such that continued emphasis on unification, especially in South Korean politics, is a likely impediment to progress.


Introduction
Efforts to convince the Democratic People's Republic of Korea (DPRK or North Korea) to abandon its nuclear-weapon aspirations and programs have been stuck in a wash-rinse -repeat cycle going on three decades. Carefully negotiated incremental steps and expertled processes failed to survive the inevitable political hurdles, technical setbacks, and mutual recriminations that beset the 1994 Agreed Framework, the 2005-2008 Six Party Talks, and even the short-lived 2012 "Leap Day Deal". Six DPRK nuclear explosive tests and multiple launches of long-range ballistic missiles are proof positive that a new method, based on a different logic, is needed to achieve denuclearization of the Korean Peninsula and, beyond that creation of a nuclear-weapon-free zone in Northeast Asia (NEANWFZ).
The remarkable June 2018 Singapore Summit between Chairman Kim Jong Un and President Donald Trump seemed to herald just such a needed new approach. The summit affirmed the prospect that direct, leader-to-leader negotiation between the DPRK and the United States could break apart the centripetal forces binding the cycle of failed nuclear diplomacy. The two leaders agreed, in essence, to subvert the old logic, which cast peace as a function of North Korea's nuclear dismantlement. The Singapore Summit changed the math: the creation of a "lasting and stable peace regime" could be solved simultaneously with the "complete denuclearization of the Korean Peninsula". 1 This shift to focus on peace and normalization of relations among the combatants of the 70 years past Korean War implicitly recognizes that DPRK leaders are unlikely to relinquish nuclear weapons unless and until they achieve regime security.
Lamentably, in the months following the Singapore summit, despite additional highlevel summitry, Washington and Pyongyang struggled to translate this new logic into sustained concrete action. As such, it is yet to be demonstrated that the new, "simultaneous equations" model can be more successful in moving the Korean Peninsula toward denuclearization than past approaches. Even so, pending diplomatic progress, it is worth examining in more detail the constituent security transformations that would be required to make the new approach workable.
Most scholarship on the future of the Korean Peninsula, especially by Western experts, focuses narrowly on steps to redress the DPRK nuclear program (Dalton, Levite, and Perkovich 2018). Recently, scholars and analysts began to work more on the process and elements of a peace regime, including plausible options and pathways that would lead from the present armistice to a new, institutionalized peace treaty, anchored by normalized US-DPRK relations (Aum et al. 2020). Over the long term, some experts even posit the development of a "security partnership" between Washington and Pyongyang (Halperin et al. 2018). Such ideas necessarily involve creating structures that remove or at least mitigate the perceived threat posed by the United States to North Korea's leaders as a prerequisite to denuclearization.
Arguably, the transformation of relations between the two Koreas is an equally important milestone on the path to a new security order in East Asia. Aside from US-DPRK diplomacy, how and in what capacity can inter-Korean initiatives contribute to the implementation of the "simultaneous equations" model? And how should such initiatives be conceived so as to facilitate progress beyond denuclearization toward an NWFZ in the region?
Although the United States poses a threat to North Korea's leaders (a threat that seems often inflated in Pyongyang's domestic propaganda), the threat from South Korea is in many ways more complicated to address, for it is not just a military threat, but also a societal one that conceivably could motivate internal regime change in the DPRK. For its part, South Korea is justifiably concerned about the DPRK's burgeoning nuclear and precision conventional strike capabilities, which prompt calls by some in South Korea for a countervailing nuclear weapons program. Diminishing perceived threats between the two Koreas will require, among other measures, profound efforts to transform their conventional military capabilities and postures and build cooperative security.

From Deterrence to Cooperative Security
One of the hurdles seemingly preventing progress toward implementing the Singapore Summit objectives is a lack of agreement between the DPRK and US leaders on how to define the "end state" to be achieved through creation of a peace regime and denuclearization 2 There are a number of vexing issues involved, including the role and mission of US military forces stationed in South Korea, the status of US extended deterrence to South Korea and Japan, the disposition of the DPRK's suspected chemical and biological weapons programs and ballistic missile inventory, and other North Korean behavior that contravenes international norms and standards. China's interests and history on the Korean Peninsula will also come into play. On top of these issues are other complex inter-Korean challenges, including disputed sea boundaries and conventional military threats. Without an agreed end state covering these issues, so the argument goes, it is difficult to know how to align and sequence the steps on the roadmap to reach it.
A common negotiating tactic when agreement on a desired end proves illusive, which could be applied to this situation, is to expand the issue set in order to subsume narrower problems. Thus, rather than haggling exactly over how to define denuclearization, for instance, US and DPRK negotiatorswith affirmation from South Korean and Chinese counterpartscould stipulate an even more ambitious destination, namely a NEANWFZ. In this way, the parties would essentially agree on the existence of a continuum of objective: peace regime and denuclearization to new security order to nuclear-weapon-free zone 3 This could remove some of the near-term sequencing and definition issues by re-framing them in terms of a larger and longer-term objective.
One of the critical trajectories along this continuum is the diminished salience of nuclear weapons to the national security policies of the states in the region. From a nuclear freeze to denuclearization and adjustments to US extended deterrence, if the parties reach an NWFZ the role of nuclear weapons would be heavily circumscribed. Yet, since nuclear weapons provide regime security to DPRK leaders, in addition to other perceived benefits, progress along this continuum must necessarily address other perceived regime threats. Put another way, North Korea's weapons are just one part of the larger deterrence construct, which also includes US extended nuclear deterrence and US-ROK combined conventional military capabilities. Kim Jong Un would also be justified in a concern about future US and ROK efforts to foment internal regime change once he gives up nuclear weapons. This is an unfortunate lesson of the "Libya model" touted by former US National Security Advisor John Bolton, among others, and roundly rejected by DPRK officials (Specia and Sanger 2018).
The bulk of policy analysis on the milestones in this continuum, especially in the United States, focuses narrowly on constructing a denuclearization roadmap. This emphasis makes sense since nuclear weapons are the most important issue for Washington. US planning clearly assumes that Washington will lead efforts to verifiably dispose of DPRK nuclear programs. South Korea and other parties would presumably play a support role on denuclearization, at least early in an NWFZ process. There has been less analysis and planning in Washington on how to change the broader deterrence framework, which is ultimately a necessary condition for progress along the continuum from peace regime to denuclearization and beyond. Most scholarship on this issue tends to gloss over this critical step. For instance, the comprehensive security approach identified by Halperin et al. seems to assume that the evolution of deterrence occurs implicitly through the normalization of relations in their six-step plan: (1) Three-party process to replace the Korean Armistice agreement (2) Declarations of non-hostility and normalization of relations (3) Sanctions relaxation (4) Financial, energy, and humanitarian assistance to DPRK (5) Northeast Asia Security Council (6) Nuclear-weapon-free zone Yet, the deterrence transformation step in the lengthy process of reaching an NWFZ deserves specific attention. Deterrence is unlikely to simply evolve automatically or organically, at least in ways that align with longer-term objectives. If deterrence is to be replaced, it must be replaced with some other concept that is consistent with the "simultaneous equations" logic, and which builds a solid foundation for an NWFZ.
Cooperative security, both as process and destination, is probably the most useful concept for guiding the shift away from deterrence. In the abstract, cooperative security "is a strategic principle that seeks to accomplish its purposes through institutionalized consent rather than through threats of material or physical coercion . . . [It] seeks to establish collaborative rather than confrontational relationships among national military establishments" (Nolan 1994, 4-5). Defining cooperative security as the desired alternative to conventional and extended nuclear deterrence is useful for several reasons. First, it focuses clearly on the conventional military balance and its coercive potential as a distinct unit of analysis. Second, it prescribes institutionalized procedures for managing relations between militaries, which over time can temper the inclination toward the kinds of tactical "provocations" that periodically drive the two Koreas to the brink of militarized crisis. And third, more broadly, it implicitly recognizes the existence and security interests of both Koreas, as separate states. Such framing subordinates unification as the predominant objective of inter-Korean relations, which could otherwise be perceived as threatening by the Kim regime.
Development of cooperative security on the Korean Peninsula is not a new idea. Along with changes in the global order in the early 1990s, scholars began to look at how military and nuclear tensions on the Korean Peninsula could be transformed using cooperative security. At that time, Western scholars tended to argue that, though cooperative security could complement constraints on North Korea's nuclear activity, ultimately the "key to resolving the dispute on the Korean Peninsula involves . . . significant economic reform in North Korea and some preliminary liberalization of its political system" (Harding 1994, 431). This formulation implicitly prescribes soft regime change in North Korea, however, which would understandably be difficult for DPRK leaders to accept.
South Korean scholarship on cooperative security grew from the late 1990 s, especially during the era of President Kim Dae Jung's "Sunshine Policy" toward the North. Like their western counterparts, Korean scholars explored ways in which cooperative security could underpin new inter-Korean relations, though focused more on complementing economic ties rather than changing the DPRK political system (Lee 2002). The freeze in US-DPRK and inter-Korean relations from 2008 resulted in a decline in scholarly work on cooperative security, even as new leadership in North Korea and its consolidation of a nuclear weapons capability changed the parameters of peace and security on the Peninsula. In 2018, when South Korea's "peace Olympics" winter games initiated a new cycle of inter-Korean diplomacy, cooperative security again became a focus of scholarship. Now, with the looming shadow of North Korean nuclear weapons, Korean scholars tend to see cooperative security less as an alternative approach to internal political and economic transformation of North Korea than as a broader framework for arms control and military confidence building (Lee 2018).

Building a Cooperative Security Foundation
Even if it is narrowly confined to conventional military measures, in parallel to work on denuclearization and a peace regime, transforming deterrence to cooperative security will be a lengthy process. It will require creation of multiple types of structures and institutions, at various levels of governance and involving multiple different actors (principally the two Koreas, but also the United States and China, consistent with their roles in a peace regime). It must be sustained by unilateral, security-building stepswhat are often termed "costly signals" in international security literaturethat demonstrate changed intentions and reduced military threats (Fearon 1997). Trust is obviously in short supply on the Korean Peninsula, meaning that leaders in Seoul and Pyongyang must employ new methods and take greater risks to overcome the significant hurdles. One such method could be a persistent investment in building inter-personal bonds, which can change how individual leaders and elites see each other and develop empathy among them (Wheeler 2018). The highly personalized efforts to cultivate leader-to-leader chemistry in the 2018 inter-Korean, US-DPRK, and Sino-DPRK summits laid an initial foundation for such trust building.
A peace regime could entail some of the initial steps to transform deterrence. For instance, Aum et al. stipulate that the peace regime must involve security guarantees to the DPRK, military confidence-building measures including conventional force reductions, and establishing a regional security architecture, all of which would modify the way in which deterrence is practiced (Aum et al. 2020). However, a peace regime by itself does not mean the end of deterrence, which is and will remain the dominant security paradigm on the Korean Peninsula for the foreseeable future. Nor is it a sufficient condition for cooperative security, which necessitates deeper efforts to reduce aggregated offensive military capability.
If and when North Korea completely disarms its WMD in the context of a peace regime, conventional military capabilities will still exist and therefore deterrence would still play some role in inter-Korean relations. It is unlikely that inter-Korean deterrence will become obsolete until there is some sort of confederations of the two states. Yet, diminishing the coercive potential of each military's capabilities on and around the Korean Peninsula is an important step toward the broader objective an NWFZ. The point here is that the timelines and milestones involved in reaching a NEANWFZ suggest that deterrence would remain a part of the picture until close to the achievement of the zone, but also that transforming deterrence is so critical to reaching the end that it must be a focus from the very beginning.
During the transition from deterrence to cooperative security, it is imperative that military-related steps mutually reinforce denuclearization objectives. Put another way, the goal is to re-shape deterrence during denuclearization to make not only nuclear weapons but also other WMD and excessive conventional military capabilities unattractive and unnecessary for Kim Jong Un to retain. Sequencing is critical. Too much focus on reducing conventional military capabilities early in the process, for instance, may have the unintended consequence of extending the denuclearization timeline if North Korea sees nuclear weapons as a useful offset for relatively weaker conventional arms.
In conceptualizing and setting parameters for cooperative security objectives, it is useful to borrow extensively from foundational work by Nolan. She argues that a fully developed cooperative security framework would set and enforce appropriate standards for the size, concentration, technical configuration, and operational practices of deployed forces. Reassurance would be the principal objective, as distinct from deterrence and containment . . .. At the practical level cooperative security seeks to devise agreed-upon measures to prevent war and to do so primarily by preventing the means for successful aggression from being assembled . . . . Thus cooperative security replaces preparations to counter threats with the prevention of such threats in the first place and replaces the deterring of aggression with actions to make preparation for it more difficult. In the process the potential destructiveness of military conflictespecially incentives for the use of weapons of mass destructionwould also be reduced (Nolan 1994, 5).
There are a number of elements that need to be considered in planning for the transition from deterrence to cooperative security. A notional but not exhaustive list includes: • Legal and political frameworks (including how to treat North-South relations) • Conventional military force posture, capability, and readiness • Political/deterrence signaling • Military incidents and accidents and preventing escalation • Inter-Korean and 2 + 2 (US/China) military and political processes • Resilience against political sabotage • Transparency and other reassurance measures As the parties negotiate agreements that address these elements, an inevitable challenge will be overcoming differing threat perceptions and asymmetric capabilities. For instance, the DPRK may prioritize constraints on the ROK's so-called Kill Chain program, which is intended for precision counterforce targeting of North Korean nuclear assets, but which is also rumored to provide a leadership decapitation capability. For its part, the ROK might insist on deep reductions or changes to the multiple rocket launch systems and heavy artillery arrayed just north of the Demilitarized Zone that threaten to decimate Seoul. It will be difficult in the first instance for the parties to agree on precise means for implementing and monitoring offensive force limitations; thus, general principles covering these various elements would be a useful starting point for discussion. In this regard, and especially in light of the specific history of military tensions sparked by DPRK "provocations," it will be crucial for the parties to reorient their military capabilities for solely defensive purposes, and to affirm that military deployments and force postures will adhere to a principle of nonprovocation (Nolan 1994, 10).

Role and Importance of Inter-Korean Initiatives
Many of the items on the list above are specific to inter-Korean conventional military deterrence. Of course, the presence of US military personnel and assets in South Korea, and broader American security interest in East Asia, bind the US-ROK alliance to this equation, albeit in a subsidiary way. However, unlike with nuclear issues which inevitably engage other powers and global regimes at a level that suppresses inter-Korean initiative, in the conventional military arena, Seoul and Pyongyang have more agency to re-make their relationship. Just as they decided in the 2018 Pyongyang Summit, the two Koreas can implement a range of discrete steps that alter conventional military relations. This agencythat Seoul and Pyongyang can take some command over the processmakes a focus on conventional military deterrence significant for inter-Korean efforts.
The extent of an inter-Korean agency may be contested, as discussed further below, but the transformation of deterrence and building of cooperative security cannot be managed or directed by other powers. The national military policies and postures of the two Koreas, and their perceptions of each other, must be altered by the two states in ways that build confidence and momentum toward larger objectives. Such steps will require political leadership, but more than this, the development of a shared will among their political elites to sustain progress. In some basic way, they must act together on their mutual desire to take greater ownership of the future of the Korean Peninsula, to minimize the role of external powers. Thus, rather than ceding too much of this issue to Washington or Beijing, Seoul and Pyongyang must lead in this process and convince others that steps they agree are the best approach.
Apart from the space available for inter-Korean initiatives in this realm, a more practical reason for prioritizing changes to conventional deterrence is the necessity of building a conflict escalation firebreak. A long-standing concern about conflict on the Korean Peninsula is that small-scale DPRK "tactical provocations" could get out of hand and lead to major war, or even use of nuclear weapons. Following two such deadly attacks in 2010, South Korea overhauled its defense approach to a "pro-active deterrence" concept that actively invites escalation through disproportionate retaliation for DPRK tactical provocations as a means of bolstering deterrence by punishment (Denmark 2011). Though understandable as a product of frustration over years of DPRK provocations, South Korea's proactive deterrence is running head-on into the consolidation of North Korea's nuclear capability in ways that compound escalation dangers. Research on state behavior in the years immediately after the acquisition of nuclear weapons suggests that leaders may be emboldened to attempt coercion or engage in risk taking during crises (Bell 2015). Thus, should there be a reprise of the 2010 incidentsa major shelling of South Korean territory or sinking of an ROK Navy vesselactive conflict might quickly erupt. Therefore, identifying and implementing measures that make conflict escalation less likely are key to making nuclear weapons less valuable both as instruments of deterrence and coercion, and ultimately to transforming deterrence.
Simplistically, the DPRK and ROK operationalize deterrence at three levels: tactical (counter-provocations, pro-active deterrence); operational/conventional (large conventional military forces, US-ROK alliance); and strategic (nuclear, US extended deterrence). One way to change the deterrence environment is to create a break in the escalation ladder that could exist between these three levels, to close conflict pathways that bring nuclear weapons into play. Practically, that necessitates a break at the operational/ conventional level of conflict. In other words, the two Koreas need to diminish the likelihood of provocationsintentional or accidentalas well as their propensity to escalate.
The 2018 Pyongyang Summit produced a Comprehensive Military Agreement that makes a modest start in this direction 4 Most of the initiatives contained in this agreement modify military practice, such as establishing no-fly zones and covering artillery batteries. A few also began to address infrastructure, like destroying guard posts. These steps are useful building blocks, and good for atmospherics. But to succeed in making a clear firebreak, bigger steps are needed to close off escalation pathways from the tactical level. In particular, both sides could signal willingness to invest security in the hands of the other party by creating vulnerabilities and demonstrating trust that the adversary will not exploit them. Destruction of guard posts along the DMZ was a symbolic step that leans in this direction, but the two sides could go further with force redeployments or dismantling of other infrastructure close to the border. Additional types of reciprocal steps that would change the fundamentals of conventional deterrence could include: • Cooperative border management including installation of sensors and joint monitoring • Asymmetric, parallel reductions or proscriptions in certain force concentrations • Fewer military exercises, with changed scope to diminish perceived offensive elements • Reduced readiness and related politico-military signaling Each of these types of measures could start with agreements in principle, followed by an implementation period, and ultimately measures for persistent or periodic monitoring.
It is necessary to recognize the importance both of transparency as a general principle, and the problematic asymmetry in capabilities between the two Koreas in the area of remote monitoring. Both Koreas will benefit from greater transparency as they seek to develop trust while they drop their guard and re-orient military capabilities toward defense. South Korea possesses satellite monitoring capabilities as well as manned and unmanned aerial reconnaissance platforms that it can use for monitoring purposes. The DPRK lacks equivalent capabilities, creating an information deficit in which trust building is inherently more difficult. Furthermore, in establishing no fly zones, the Pyongyang agreement also created unintended monitoring blindspots that make compliance verification more difficult. An obvious option that would help resolve this tension and at the same time serve as a confidence-building measure would be cooperative monitoring channeled through a standing center (such as the Joint Military Committee called for under the Pyongyang agreement). This could include the use of commercial satellite imagery or cooperative aerial overflights of agreed locations (Dalton 2018).

Constraints and Impediments
It stands as an immense challenge to translate this vision into a sequence of reciprocal actions such that cooperative security building suffuses through the denuclearization and peace regime tracks. Opposing interests, historical animosities and strongly held images of the adversary, as well as different forms of government among the parties, complicate the diplomacy required. Two such obstacles stand out. First, big power interests are likely to be a critical constraint on how far inter-Korean initiatives can progress. And second, the political construct of unification is in basic tension with the pursuit of cooperative security, such that continued emphasis on unification, especially in South Korean politics, could be an impediment.
Notwithstanding the argument above about the agency that the two Koreas can exercise in transforming their conventional military relations, the looming presence of big power interests, and those of the United States and China, in particular, is a manifest constraint. How far the inter-Korean process could adapt conventional deterrence without the US and Chinese input is a matter of debate. This issue goes beyond the presence of US Forces Korea and the UN Combined Forces Command during and after the establishment of a peace regime. The longer-term question is: how do Beijing and Washington view the Korean Peninsula in their growing power competition?
In 2017, following DPRK nuclear and long-range ballistic missile tests, China tightened the implementation of sanctions on Pyongyang to an unprecedented extent. According to some in China, tightening sanctions were not merely a signal to Pyongyang to cool its behavior, but an outward manifestation of a debate about whether a nuclearizing North Korea was more a liability to China than an asset (Li 2017). When diplomacy resumed in 2018, that debate in China effectively concluded in favor of those perceiving North Korea as a future asset. Not wanting to be sidelined during US-DPRK diplomacy, and to protect against a future US-DPRK alignment, China abruptly switched tracks from pressure to diplomacy. Over a 15-month period starting in March 2018, Chinese President Xi Jinping met five times with Kim Jong Un. Whereas the United States is concerned primarily with denuclearization, as a neighbor of North Korea China's interests are far more complex.
Chinese preferences in the construction of a peace regime and changes in inter-Korean deterrence could play out in different ways. For instance, China might pressure North Korea not to accept US and ROK military capabilities that are directed at Beijing. It could also encourage North Korea to retain some types of medium-range missile capabilities that threaten US bases in the periphery of the Korean Peninsula as a means of deterring US theater operations. China might also exert greater coercive pressure on South Korea, as it did after Seoul opted for US deployment of the THAAD missile defense system in 2016. Chinese pressure through any of these vectors will constrain inter-Korean flexibility.
Just as China debated whether North Korea would be an asset or liability, some western analysts also question whether North Korea could in the future be a US security partner or ally in the region (Halperin et al. 2018). DPRK leaders may seek such an alignment with Washington precisely to protect against future Chinese coercion as Beijing's assertiveness grows in its near abroad. That said, it seems doubtful that US officials could convince themselves that the benefits of a security partnership with North Korea would outweigh all of the negatives, such as Pyongyang's horrific human rights abuses, autocratic governance, and illicit economic activity, not to mention the potential damage to the US alliance with South Korea.
Even if US-DPRK alignment seems far-fetched at this remove, US analysts may begin to see the future of the US-ROK alliance increasingly through the lens of power competition with China. As noted above, China expressed great concern in 2016 about US-ROK missile defense cooperation and is vehement in its opposition to a US-ROK-Japan regionally networked missile defense architecture. As the United States seeks means to challenge China's growing power projection capabilities in East Asia, it may ask its alliance partners to develop capabilities, and/or agree to deploy US systems that are oriented toward China. It is possible, for example, that Washington might seek to base intermediate-range ground-launched ballistic missiles in South Korea as a way to balance China's regional missile threat. Thus, to the extent that Washington attempts to focus the US-ROK alliance on containing Beijing, that could impose limits on South Korean flexibility in adapting conventional deterrence with North Korea.
Whereas external, big power interests might narrow space for inter-Korean efforts to develop cooperative security, adherence to the principle of unification in the national policies of the two Koreas may pose a different kind of impediment. It might seem impolitic to state it so baldly, given the emotion and trauma associated with perpetuation of the division of the Korean people, but unification looks an increasingly remote prospect. North Korea's nuclear weapons give Kim Jong Un added insurance against external regime change. Kim's consolidation of power after what appeared to be a tenuous leadership transition in 2011 following the death of his father, Kim Jong Il, suggests regime collapse is also unlikely. Even partial unificationsuch as a confederation of separate statesis out of reach. Moreover, the two states retain fairly mutually exclusive visions about which political system would rule a unified Korea. In this sense, continuing to pursue unification as the primary objective of inter-Korean relations is logically inconsistent with a process to develop cooperative security, and probably retards the potential for cooperative security to undergird denuclearization and build a peace regime.
Probably, neither state could publicly renounce the objective of unification. Particularly in South Korea, the political costs would be immense. Yet the burden is greater for South Korea to reduce its emphasis on unification, at least insofar as the idea of a unified Korea under Seoul's leadership is perceived as a threat in the North that justifies continued possession of nuclear weapons. If cooperative security is to be part of the long-term path toward peace and stability on the Korean Peninsula, it must be approached on the basis of preserving separate states (and by extension the Kim regime), rather than trying to unify them.
Unification is written into the South Korea constitution, article 4 of which declares, "The Republic of Korea shall seek unification and shall formulate and carry out a policy of peaceful unification based on the principles of freedom and democracy". In 1969, then South Korean Park Chung-Hee formed a National Unification Board, which President Kim Dae Jung elevated in 1998 to become the Ministry of Unification charged with implementing his Sunshine Policy. The roughly equivalent DPRK entity is the United Front Department, which in addition to managing inter-Korean diplomacy has intelligence and propaganda functions. Subsequent conservative governments in Seoul considered disbanding or downgrading the Ministry, apparently for more political than strategic reasons (Voice of America News 2009). Setting politics aside, however, altering the Ministry's status or function to better support long-term cooperative security objectives, and to reduce the prominence given unification in South Korean policy, would better align with geopolitical realities.
The trajectory of public opinion in South Korea may favor a shift toward cooperative security instead of unification. One 2018 survey by the Asan Institute for Policy Studies shows that younger South Koreans are increasingly likely to see North Koreans as strangers, rather than as having a shared ethnicity, which helps explain lower interest among younger cohorts in unification (Kim, Kildong, and Chungku 2018). A 2019 opinion poll by the government-affiliated Korea Institute for National Unification indicates that among all age groups there appears to be growing, albeit still relatively small at 20%, support for peaceful coexistence instead of unification. The report concludes "Younger generation, conservatives, supporters of [the conservative] Liberty Korea Party, women, etc. have a clear tendency to prefer peaceful coexistence over unification" (KINU 2019, 5). Thus, generational change in South Korea could play an important role in broadening political support for cooperative security.
Big power interests and continued emphasis on a unification construct could pose obstacles to inter-Korean effort to transform deterrence and build cooperative security. Or not. With shared political will, Seoul and Pyongyang can decide to minimize the obstacles to stable, peaceful, and cooperative relations. This interest is made clear in the preamble to the 2018 Panmunjom Declaration, in which the leaders of the two Koreas asserted a "firm commitment to bring a swift end to the Cold War relic of longstanding division and confrontation, to boldly approach a new era of national reconciliation, peace and prosperity, and to improve and cultivate inter-Korean relations in a more active manner". 5

Conclusion
In their three inter-Korean summit meetings in 2018, President Moon Jae In and Chairman Kim Jong Un expressed a clear, shared desire to take more ownership of the future of the Korean Peninsula and dismantle the frozen Cold War security structures. Diminishing the salience of nuclear weapons, transforming deterrence and establishing cooperative security are necessary elements of a long-term approach to peace and security on the Korean Peninsula.
The political breakthroughs in inter-Korean and US-DPRK relations in 2018 showed that a new path toward peace is conceivable. Unfortunately, progress along this path stalled in 2019, and even suffered some reversals. US-DPRK discussions on implementing the Singapore Summit failed to achieve concrete results, which had negative spillover effects on inter-Korean relations. If new opportunities for progress materialize, the two Koreas could take several steps to build confidence and develop a solid foundation for cooperative security. For instance, they could add transparency measures to the 2018 Pyongyang Comprehensive Military Agreement. They could also define a common vision for peace and security, with a specific articulation of cooperative security as the basis for that vision. Necessarily, this would require the two sides to downplay unification as the overarching construct for this future. And they could also expand the contours of a desired end-state to specify the establishment of an NWFZ in the region.
Imagination, persistence and risk-taking by the leaders of the two Koreas are imperative if they are to escape the negative cycle of failed security diplomacy gripping the Peninsula. Reshaping mutual security by transforming conventional military deterrence is a significant way in which inter-Korean initiatives can spur progress in implementing denuclearization and building a peace regime, and ultimately concluding a NEANWFZ.

Disclosure Statement
No potential conflict of interest was reported by the authors.

Funding
This work was supported by grants from the Carnegie Corporation of New York and the John D. and Catherine T. MacArthur Foundation.

Notes on Contributor
Toby Dalton is co-director of the Nuclear Policy Program and senior fellow at the Carnegie Endowment for International Peace in Washington, DC. Before joining Carnegie, Dalton served in several capacities at the US National Nuclear Security Administration, including as senior policy advisor in the Office of Nonproliferation and International Security. He also served as a professional staff member of the US Senate Foreign Relations Committee and was a Luce Fellow at the Institute for Far Eastern Studies in Seoul, South Korea. He holds a PhD in public policy from George Washington University.