Deterrence and Detente on the Korean Peninsula

This post is authored by Brad Roberts, director of the Center for Global Security Research at Lawrence Livermore National Laboratory in California. It is part of a project conducted by the program on U.S.-Korea policy at the Council on Foreign Relations, supported by the Smith Richardson Foundation and Korea Foundation. This series of posts will address the U.S. nuclear posture in Northeast Asia, implications of North Korean nuclear and missile programs for U.S. extended deterrence commitments, operational and tactical dimensions of deterrence on the peninsula, and regional dimensions of stability. To further stimulate an open discussion of these issues, we would like to invite reader responses. Please contact Ellen Swicord at [email protected] for submission guidelines if you are interested in contributing a response.

In the current moment of uncertainty and debate in the U.S.-ROK alliance about how to proceed in dealing with North Korea, it is useful to look for lessons in the experience of the transatlantic alliance.  For decades, NATO has debated how to best balance deterrence and détente. The debate has its origins in the 1960s, as NATO adjusted to a changing world, and the Harmel Report of 1968, which argued that alliances serve both military and political purposes and must set agendas to maintain adequate defenses while promoting dialogue with the aim of resolving conflicts. NATO has also debated how to ensure that its deterrence and defense posture remains “fit for purpose” in an ever changing security environment. NATO heads of state and government have for decades repeatedly  expressed a commitment to maintain an “appropriate mix” of nuclear and non-nuclear capabilities for deterrence at the lowest levels necessary in the security environment as it exists.

The necessary balance between deterrence and détente is nowhere in more debate than in Seoul. On the one hand, there is broad agreement that the peace process with the North should be given a chance. This persists despite widespread disagreement about its prospects for success. In order to give peace a chance, various forms of military restraint have been put in place, including the cancellation of major exercises. Also on hold are the joint U.S.-ROK efforts to strengthen and adapt the regional deterrence architecture that began a decade ago. On the other hand, there is widespread recognition that North Korea continues to develop its deterrent forces even while engaging in the détente process. There is also rising concern about the negative impacts of China’s military modernization on the regional security environment. Thus in Seoul there is a rising debate about whether and how long to sustain the current deterrence restraint. As I heard repeatedly in a recent visit: “give peace a chance…don’t let the deterrence agenda get in the way…but will we know when it’s time to give up our cautious optimism?” 

What should be done? How should deterrence and détente be balanced in the current circumstances?

Strengthening Deterrence, 2010-2018

The need to strengthen the alliance’s deterrence posture is not new. A decade ago, in recognition of the emerging nuclear and missile threat from the North, the U.S.-ROK alliance committed to a joint effort to strengthen and adapt the regional deterrence architecture to address new challenges. To that end, they agreed to tailor deterrence strategy, including extended nuclear deterrence, to new circumstances. To focus this effort, the bilateral Extended Deterrence Policy Committee (EDPC) was formed in 2010. The EDPC helped identify the necessary adaptations through joint studies and analysis, including with the use of tabletop exercises. In 2012 it produced a tailored deterrence strategy to guide bilateral planning and force development. In April 2015, the EDPC and the Counter-Missile Capabilities Committee merged to become the Deterrence Strategy Committee (DSC). In 2016, an additional venue was added within the 2+2 framework, called the Extended Deterrence Strategy and Consultation Group, to address broader regional security issues. The Trump administration has continued the dialogue on deterrence and the process of adapting the U.S. deterrent, as reflected in its reviews of nuclear and missile defense policy and posture. But there appears to be no practical agenda for further steps at this time to strengthen and adapt the regional deterrence architecture at this time. 

Pursuing Détente from 2018

The process of dialogue and summitry has not yet taken a decisive turn to success or failure. At this time, we can conceive of three possible outcomes.

First: definitive success. This would bring a peace treaty, denuclearization, and the termination of the United Nations Command. Whether it would also bring an end to the U.S. role as a security guarantor on the peninsula is an open question. A key uncertainty would be the extent to which China is seen as a military threat. 

Second: definitive failure. This would bring a renewal of “maximum pressure” and debate about whether something more is needed in the way of preventive war, given the failure of the pressure campaign in this scenario. This would stoke great anxiety about the credibility and effectiveness of the alliance’s deterrence posture and the U.S. extended nuclear deterrent.

Third: stalemate. This would bring incomplete progress—an armistice without a peace agreement or denuclearization, or perhaps a peace agreement without denuclearization. An alternative outcome could involve removal of the North Korean threat to the United States but not to South Korea or Japan. These outcomes would stoke great anxiety about deterrence. Peace without denuclearization would bring especially complex questions about the future of U.S. extended deterrence.

As of spring 2019, we face neither clear success, nor clear failure, nor stalemate, but prolonged uncertainty. There is piecemeal progress on détente, but also continued evidence of North Korea’s further development of a medium-sized nuclear strike force. Anxieties about the consequences for the balance of confidence in the separate deterrent postures of the North and South are taking shape in Seoul. A rising sense of vulnerability has driven new debates, including deliberation over whether to maintain the posture of deterrence restraint or return to strengthening. 

Some in Seoul argue that the Deterrence Strategy Committee should stand down entirely while the experiment in peace-making proceeds, as another sign of good faith by the U.S.-ROK alliance to help renew momentum. This is a distinctly minority view. Others in Seoul argue that the DSC should continue to identify steps to strengthen deterrence and that the alliance should take them, given the advances North Korea is making in operationalizing its nuclear deterrent. This too is a minority view. The majority view is that the effort to identify potential next steps in the strengthening and adaptation process should continue, but that those steps should be held in reserve for the moment. 

In my assessment, the DSC process can serve three useful purposes in the current period of uncertainty. It can serve as a hedge against a breakdown of the peace process by defining what the alliance would be prepared to do in such a contingency. It can also serve as an incentive for Kim Jong-un to stay at the table by reinforcing the alliance’s message that further pursuit of nuclear capabilities will bring not advantage but risk. Finally, it can serve as a partial foundation for exploring how deterrence challenges might evolve over the coming decade if and when competition for advantage in cyber space and outer space intensifies.

At this time of uncertainty, the alliance needs a strategy that supports best-case outcomes but also hedges against worst-case scenarios. Harmel would advise that because the alliance serves both military and political purposes, it should sustain the process of strengthening and adapting deterrence while continuing to pursue denuclearization. But it doesn’t make sense to put this approach front-and-center in the alliance’s public diplomacy. Until there is some clarity about the results of the current détente and the real prospects for denuclearization, further steps to strengthen the alliance’s deterrence posture should speak for themselves. As one expert in Seoul put it, let’s keep the process “on simmer.”

Back to the NATO Analogy

As the U.S.-ROK alliance tries to re-balance deterrence and détente in light of new evidence about Kim’s intentions and rising anxiety in the South, we should expect an intensifying political debate. But when it comes to deterrence, we should not simply expect a return to the discussion that was underway before the Trump-Kim opening. Rather, we should expect a different debate—one involving more difficult questions for the United States. What is the “appropriate mix” of deterrence and defense capabilities for the U.S.-ROK alliance?  What would make it “fit for purpose?” 

Over the last decade, the U.S.-ROK alliance has sought to strengthen its deterrence posture comprehensively with political measures to signal collective resolve, strong leadership messages, a balance of conventional forces favorable to the alliance, improved long-range strike capabilities, missile defenses, resilience in cyber space, and what the United States calls “a tailored nuclear component.” That is, the United States has maintained (and is modernizing) the ability to deploy nuclear bombs into the region with both strategic and non-strategic aircraft, with the expectation of potentially doing so during mounting political-military crisis. It has also committed to two supplemental capabilities in the U.S. nuclear posture for bolstering extended deterrence. The United States backs these capabilities with a clear declaratory policy, reserving the right to employ nuclear weapons when the vital interests of an ally are at risk. 

Both capitals have broadly supported this overall approach over the last decade. But a minority camp deems it inadequate and its voice is becoming more insistent. Policymakers in the United States should expect a spike of interest in South Korea in restoring a permanent U.S. nuclear presence (all U.S. nuclear weapons were removed from South Korea at the end of the Cold War). They should also expect a rising debate in South Korea about whether it should provide for its own nuclear deterrence requirements if the United States is unwilling to do so.

What about “fit for purpose?” Over the years I have regularly heard South Koreans argue that “the nuclear deterrence you give your European allies is more and better than what you give your Asian allies.” This argument has become much more frequent and impassioned, despite persist U.S. efforts to explain the logic of the different extended deterrence postures in Europe and Asia. There is a steadily rising demand in Seoul for “NATO-like” nuclear deterrence arrangements, but there are many misperceptions of what “NATO-like” actually means.

NATO’s nuclear deterrent has three main elements. The first is political: high-level political statements about the roles of nuclear weapons in alliance strategy, along with supporting declaratory policies from the capitals of its three nuclear-armed members. The second is military-technical: the capabilities to employ nuclear weapons. For NATO, this means the “sharing arrangements” provided by fighter-aircraft certified for both conventional and nuclear munitions, which are operated by some NATO members and prepared to deliver weapons in war under the authority of the U.S. president. These offer deterrent value because they demonstrate to potential adversaries that an attack on one will be treated as an attack on all and will necessarily implicate the United States in a response. The third is procedural: a consultative process that informs policy development and planning in peacetime, that would inform leadership decision-making in a crisis, and that would share the burden of decision in war. 

Some of these elements are already in place in the U.S.-ROK alliance. Additional elements might be adopted and new elements might be created. Each would involve benefits, costs, and risks, though advocates and opponents of different options generally focus on only one aspect or another.  In assessing costs and risks, it will be important to look beyond the peninsula for the consequences of different U.S.-ROK deterrence postures for regional security more broadly and for the global nonproliferation regime.

In sum, the next big deterrence debates in the U.S.-ROK alliance will likely focus on the needed “tailored nuclear component” that will be “fit for purpose” for deterring a North Korea that has not denuclearized. As nuclear policy is inherently controversial, stakeholders in a sound approach should start the homework required to promote informed debate now.

The views expressed here are those of the author and should not be attributed to any institution with which he is affiliated.