Why is a phased approach to denuclearization necessary, and what might a notional road map look like?

After declaring “the accomplishment of the great, historic cause of perfecting the national nuclear forces,” North Korean leader Kim Jong-un will not simply agree to hand over immediately his nuclear weapons and destroy the nuclear and missile enterprise carefully built over the last several decades. This holds true even if North Korea agrees to the ultimate goal of denuclearization, as well as an interpretation of denuclearization to mean dismantling of nuclear weapons and associated infrastructure. No amount of sanctions or other “maximum pressure” will force North Korea to undertake such comprehensive denuclearization forthwith. Such a result could only conceivably be achieved—if it can be achieved at all—through a protracted process of tedious negotiations and even more protracted implementation that would persuade Kim Jong-un and his allies that they could genuinely trust the US security guarantees against external threats, and at the same time also count on considerable and sustained economic and political rewards that would forestall internal challenges to the regime.

Practically, charting a path to comprehensive denuclearization will require several phases of activity, for the simple reason that neither Washington nor Pyongyang will agree to front-load the process with the most sensitive or expensive concessions. Even if they would miraculously show some political flexibility on this count, the process itself would inevitably consume many months, probably even years. Negotiating the breakdown of the phases, their sequencing and timeline, and the reciprocal steps that would facilitate the attainment of each will be a complex undertaking given the varied interests and concerns of the parties involved. (During these negotiations, Washington would also have regular consultations with Tokyo and Seoul to ensure their interests are covered.) And this still leaves the challenge of implementing agreed steps and verifying their completion to mutual satisfaction. The actual elimination of nuclear capabilities and the expensive, time-consuming dismantlement of infrastructure will necessarily occur in a later phase, if ever. Realistically then, the road map to denuclearization would inevitably lead through a midterm objective. This should be a comprehensive, verifiable capping (CVC) of the entire nuclear weapons program including its weapons delivery capability.

A first phase, which could be accomplished as a result of the ongoing summitry, could anchor the denuclearization goal, commit to immediate de-escalatory steps, and establish a broad framework for negotiations. The centerpiece would be commitment to begin technical negotiations that would cap, constrain, and ultimately reduce North Korea’s nuclear and missile programs, and set a realistic timetable for attaining this waypoint. To sustain these negotiations, the parties would need to enumerate quickly a list of provocative actions that both sides would agree not to undertake during the course of negotiations.

For the United States, this list could include all nuclear and missile tests, stopping plutonium and tritium production, stopping all uranium enrichment activity outside the nuclear center at Yongbyon, and other steps to stop North Korea building up its nuclear arsenal. For North Korea, the list might include U.S. cessation of overflights of B-52 bombers during military exercises and taming the scope and orientation of such exercises. Verifying that neither party is violating the no-provocations agreement could be done mainly through national remote monitoring capabilities and ongoing sanctions enforcement activity. It could be advantageous to introduce the International Atomic Energy Agency (IAEA) early in a technical support (not investigative) role related to nuclear safety and security, as well as other broad-based science and technology collaboration with North Korean scientists in order to provide some tangible early demonstration of the potential benefits of sticking to the denuclearization path.

A second phase could comprise a comprehensive, verifiable capping of North Korea’s nuclear and missile programs. The objective in this phase would be to stabilize the situation by preventing further development or augmentation of North Korea’s nuclear arsenal. It would require, among other measures, freezing production of all fissile materials, missiles, and missile transport and launch vehicles. North Korea would be required to provide comprehensive declarations of its activities and stockpiles and ultimately subject them to monitoring and verification, even while it retains its existing nuclear arsenal, albeit in a recessed mode. The fissile material monitoring and verification activities could be undertaken by the IAEA, while the United States, China, and perhaps Russia could verify nuclear-weapons-related and other activities. Cooperative threat reduction tools could also be introduced in this phase to redirect North Korean nuclear and missile scientists to other lines of work.

If a comprehensive, verifiable cap could be negotiated and faithfully implemented, then the key prerequisites for actually dismantling North Korea’s arsenal would be met and the odds of moving forward would begin to improve. Achieving these steps would enhance the security of all parties involved, so there is merit to reaching a sustainable cap not only as a waypoint to denuclearization. Once capping is in place, a third phase of negotiations could commence, aiming to decommission and eliminate the nuclear weapons complex and all associated materials. At this stage, North Korea would not only have to cede the weapons and the infrastructure, but also have to undertake changes in its laws and policies to proscribe possession of nuclear weapons.

There are also the important matters of North Korea’s chemical and biological weapons programs and its large conventional military forces, which pose additional complications in conceptualizing a denuclearization road map. It is important to address other WMD programs in parallel, given the obvious threat they pose. Declarations, verification, and capping of chemical and biological weapons stocks and infrastructure should be sequenced to follow nuclear capping, while dismantlement and destruction should be coincident with dismantlement of nuclear weapons infrastructure in the third phase.

North Korea’s conventional military forces are entangled in this process two ways: in relation to progress on pacifying the Korean Peninsula, and as a potential cover for prohibited activities. In the near term, the de-escalation objectives included in the Panmunjom Declaration indicate a potential avenue to temper conventional military threats. The practical challenge in the intermediate phase is to find suitable verification arrangements that cover the entire nuclear weapons program, and subsequently the chemical and biological ones as well. These arrangements must deny North Korea the option to conceal banned activities under the guise of conventional military capabilities, while still refraining from infringing on sensitive conventional military operations. The comprehensive verification approach described below accounts for this challenge.

This notional road map primarily illustrates one side of the equation—introducing constraints and ultimately rolling back North Korea’s nuclear capability—without addressing the other, namely what the United States and others would agree to provide in return. That is no less formidable a challenge. Beyond the widely discussed political, security, and economic incentives that will need to be proffered, there is potential value, and no risk, in immediately offering scientific and technical collaboration with North Korea in purely civilian projects, and to offer funding to employ in such projects North Korean technical cadres that would be displaced from the nuclear program.

* Abridged version of a detailed road map.

How have developments since 2005 made a phased approach the only viable path?

The circumstances surrounding potential negotiations with North Korea to roll back its nuclear weapons program are different from previous efforts in two fundamental ways.

First, North Korea now possesses nuclear weapons, and it seeks international recognition of that fact. In 2005, North Korea had not yet conducted a nuclear test and its medium-range ballistic missile program was rudimentary. Today, following six nuclear explosion tests, North Korea possesses an arsenal of weapons and has a large indigenous infrastructure to sustain and advance it.

North Korea’s sixth nuclear test, conducted in September 2017, achieved a much larger yield than prior tests, lending credence to North Korea’s claim that it possesses a more powerful hydrogen bomb design. Its intercontinental ballistic missiles could most likely target the United States, even though the reliability and safety of both as well as their operational robustness remains highly uncertain. The combination of embryonic long-range ballistic missiles and hydrogen bombs capability now means North Korean can threaten unacceptable damage against the United States. This capacity could be greatly improved if left unchecked for much longer. This situation poses a very difficult challenge to the credibility of the United States’ commitment to defend South Korea and Japan in a future conflict with North Korea.

Second, today there are more effective international sanctions in place that create leverage on North Korea that didn’t exist in 2005. Successive UN Security Council resolutions and more rigorous enforcement efforts, in particular by China, are biting the North Korean economy. The distorting effects of these sanctions, particularly should China and Russia continue to implement them fully, will grow over coming months. Chinese concerns about North Korea’s nuclear threats appear to be driving Beijing to support greater—if not maximum—pressure on Pyongyang. But sanctions alone are unlikely to result in pressure sufficient to force North Korea to agree to immediate denuclearization.

So negotiations must contend with the reality that North Korea possesses nuclear weapons and is highly unlikely to trade them away any time soon. Thus, the problem of negotiating constraints and rollback has become infinitely more complicated. An agreement to freeze production of the bomb fuel plutonium and highly enriched uranium—which was the main focus of both the 1994 Agreed Framework and 2005 Joint Statement—would no longer constitute a serious and meaningful constraint on North Korea’s nuclear program. It would not stop the maturation of the most immediately threatening and destabilizing North Korean capabilities.

Given the improbability of negotiating complete and immediate denuclearization, and the urgency to stop further qualitative improvements and growth in the size of North Korea’s nuclear arsenal, a sensible approach is to retain the aim of complete denuclearization, but for the foreseeable future focus diplomacy on achieving a comprehensive, verifiable cap on the entirety of North Korea’s nuclear and missile capabilities. Such negotiations would still be exceptionally complicated and time consuming, but they are indispensable for eventual disarmament and have a higher probability of yielding progress soon that would be beneficial to the security of the United States and its allies in the region

Since North Korea is unlikely to give up all of its nuclear and missile capabilities immediately, what are the most important ones to block?

Despite recent successes, the limited number and scope of North Korea’s missile and nuclear tests means that the reliability of both the intercontinental missile systems and the hydrogen bomb design are probably not high. In particular, North Korea most likely has not carried out sufficient testing of the full integration of these complex systems. The current self-imposed moratorium on missile and nuclear testing by North Korea means that it is not currently able to do such full-scale testing.

In order to block further qualitative and quantitative enhancements to North Korea’s nuclear arsenal and its operational capability, the United States should focus on several important priority restraints early in negotiations. The first of these is maintaining and codifying a ban on missile, ground and flight tests and nuclear explosive tests, the latter to include so-called subcritical tests that can help validate weapons design without creating a nuclear yield, as well as other weaponization work. This would be the most effective means of blocking North Korea from improving its confidence in the reliability of its long-range missiles and its bomb designs. The missile test ban should also extend to the nascent submarine-launched ballistic missile that North Korean scientists are developing, to include ejection tests from submerged test barges.

A related priority activity to block is further research and development of large solid-fuel rocket motors. Unlike the liquid-fuel motors North Korea currently uses for its long-range missiles, which take several hours to fuel and ready for launch, solid-fuel missiles could dramatically improve the survivability, mobility, and readiness of North Korea’s nuclear arsenal. Such arrangements also would have to ensure that North Korea’s satellite launch program does not serve to bypass restrictions on ballistic missile developments.

Negotiators should also seek to block further production of the large transporter-erector-launchers that North Korea uses to move and deploy its long-range missiles. Stopping production (as well as imports of any necessary components North Korea is not able to produce domestically) of these vehicles would introduce import constraints on the size and mobility of the nuclear weapons most threatening to the United States.

Although North Korea is thought to already possess enough fissile material for an arsenal of perhaps thirty to fifty nuclear weapons, it is important to stop its stockpiling of additional plutonium and highly enriched uranium. This would require a stop in operations of the nuclear reactor and reprocessing facility at Yongbyon, and agreement by North Korea not to start a new, experimental reactor that may be nearing completion. Shutting down the Yongbyon reactor (while banning commissioning of any other reactor capable of generating military grade plutonium) would also have the virtue of degrading North Korea’s ability to produce another important material—tritium—that it probably utilizes in its hydrogen bombs.

Finally, North Korea has said it will not export weapons of mass destruction, though it has in the past. Hence negotiators should seek additional means of monitoring exports to ensure this promise is being met, and to ascertain that North Korea does not build a program elsewhere offshore. This regime also ought to verify that North Korea does not continue to engage in procurement to advance its clandestine nuclear program.

Reaching early agreement to stop these activities would set the stage for a second phase comprehensive capping of the entire nuclear and missile enterprise. It would also help insulate further negotiations from potential provocations if all of these activities were understood to be prerequisites for further progress. Moreover, as North Korea ceases work in these areas, there will be opportunities to begin redirecting idled scientific staff into alternative project work away from nuclear and missile fields.

Is it possible to detect and stop cheating?

Monitoring and verification of any nuclear program is a complex technical and political challenge. In a country as opaque as North Korea, this challenge is compounded by lack of multiple sources of information to help validate assessments. The previous Six-Party denuclearization negotiations with North Korea broke down in 2008 primarily because of disagreement about when and how North Korean declarations of nuclear activities and material stockpiles would be verified. Developments since 2008 have compounded the problem of detecting cheating and verifying compliance, since the range of activities, facilities, and personnel to be monitored is far greater.

There is a clear tension between the scope of a potential capping agreement and the certainty of detecting aberrant behavior. There are relatively few North Korean nuclear activities that the United States and others could monitor and verify at a level approaching 100-percent certainty without persistent, on-site access—essentially nuclear explosive tests, missile launches, and operation of the Yongbyon reactor. However, the scope of the North Korean nuclear and missile enterprise at this point is sufficiently broad that confining verification activities to only those for which observers have high confidence would exclude prohibitions or constraints on activities of great relevance in terms of preventing breakout and/or further advances in North Korea’s capabilities. These could include subcritical nuclear tests, missile production, improvements to missile reentry vehicles, and de-mating of warheads and delivery vehicles, for instance. Yet the secretive nature of the North Korean regime, and its anxiety about compromising all of its sensitive assets (including conventional military ones), would inevitably complicate and drag out the implementation of arrangements granting foreign inspectors unfettered, permanent, and nationwide access to all sites and activities of concern.

It thus makes much more sense to encompass all key North Korean activities in a capping arrangement, and to rely on multiple approaches to verify compliance. A probabilistic comprehensive verification approach, based on tailoring transparency and inspection protocols to specific restricted or prohibited activities and capabilities, would provide a more viable short- to mid-term tool adequate for detecting and thereby deterring noncompliant behavior by North Korea. This option to attain sufficiency of verification during a capping phase has more merit than the traditional, legalistic approach to verification, which would have to be reserved for the final phase of the denuclearization process. Comprehensiveness in scope of the items subject to monitoring and inspections greatly enhances the prospects of overall detection of any transgressions. This in turn diminishes the prospect and utility of North Korean cheating on individual items.

To illustrate the logic of a probabilistic comprehensive verification approach, consider a capping agreement that proscribes ten activities or capabilities. Even if only three proscribed activities can be verified with near-certainty, North Korea will still face the prospect that cheating on one or more of the other seven could be detected by some means. (North Korea would not know with certainty the probability of detection.) And, if the overall agreement holds that violation of one or more of the terms is a violation of the whole agreement, then the United States would be much better off than if an agreement only covered the three items that can be monitored with great confidence. Appreciating the power of probabilistic verification may pose a political/cultural challenge in Washington, but the practical strategic merit is clear.