What North Korea Means – and Doesn’t – for Nuclear Deterrence
Image Credit: Flickr / John Pavelka

What North Korea Means – and Doesn’t – for Nuclear Deterrence


The Democratic People’s Republic of Korea (DPRK) — North Korea — is an ongoing awkward case for the international community. Despite different approaches and efforts over decades to denuclearize the Korean peninsula, North Korea has developed a nuclear arsenal and continues to carry out nuclear test detonations, most recently on September 3. Moreover, it continues to improve its missile delivery systems, clearly with a view to fielding intercontinental ballistic missiles (ICBMs) able to strike targets as far away as its nuclear-armed adversary across the Pacific. Its latest missile test — over Japan once more — came days after the adoption of the latest round of United Nations sanctions in response to its sixth nuclear test.

With no end to the crisis in sight, proponents of nuclear deterrence have spun the North Korean case as proof of the futility of any international effort to move away from continued reliance on nuclear weapons for deterrence. For instance, France, the United Kingdom and the United States jointly condemned the new UN Treaty on the Prohibition of Nuclear Weapons, adopted by 122 countries, on the grounds that it “offers no solution to the grave threat posed by North Korea’s nuclear program, nor does it address other security challenges that make nuclear deterrence necessary.” Yet other approaches to tackling North Korea’s WMD-related programs have not been conspicuously successful either. Nor was it anyone’s intent in the ban treaty negotiations to presume to devise a solution tailored to North Korea.

That the difficulty of dealing with North Korea is being used as a prop to support existing policies and practices of nuclear deterrence is worth study. On the face of it, the presence and readiness to use nuclear weapons in Northeast Asia would seem to be the security problem, not the solution. Yet nuclear deterrence proponents argue that nuclear weapon-based deterrence is, in effect, the only way to contain the North Korean regime, while ignoring the asymmetric security dynamics that led to this situation — and where it might lead. Even were such a claim true, it simply does not follow that it validates continued reliance on nuclear deterrence in other regions or contexts, especially in view of our improving level of understanding of the sheer spectrum of causes of risk of inadvertent or deliberate nuclear use, and of the “near misses” that have occurred in the nuclear age.

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Instead, the case of North Korea underlines the not-insignificant risks associated with nuclear weapons in any hands, including the ways in which this distorts the security perceptions and choices of others. In this sense, North Korea is revealing on at least three counts for wider nuclear weapons policies and practices. Firstly, the relative lack of predictability of North Korea’s leader, Kim Jong-un, expose inherent contradictions in the notion of stability founded upon nuclear deterrence. Secondly, while North Korea’s opacity is extreme, lack of transparency is characteristic of the nuclear weapons program of all of the nuclear-armed states. Thirdly, Pyongyang’s brazen threats reflect a systemic normalization of the nuclear warfighting “option.” While other nuclear-armed states refrain from similar rhetoric, they have invested substantially to enhance the effectiveness, flexibility, and thus, the usability of nuclear weapons — a trend that should elicit greater concern.

This article briefly explores each of these three points and considers what this means for nuclear weapon-risk reduction on a global scale.

The “predictability” of nuclear deterrence

It is worth recalling that nuclear deterrence emerged, intellectually and doctrinally, in a Cold War bipolar environment in which nuclear weapons were already being deployed. After the particular scare of the 1962 Cuban missile crisis, special emphasis and effort was placed by policymakers and theorists on both sides on notions of strategic stability and — in the U.S. context — on the rationality of policymakers in order to avert the death and destruction that would be brought upon by nuclear use, while at the same time making every preparation for such use. Yet even at the time nuclear deterrence wasn’t necessarily widely considered as realistic, as in the 1950s and 1960s “there was no evidence on which to base claims that the arms race… would end peacefully.” That things turned out as they did indicates good luck played a part to a degree that appears under-appreciated today.

This raises discomforting questions about the Korean situation. Can Western nuclear decision-makers be confident that the North Korean leadership understands deterrence in the same way they do, and for that matter are persuaded that it might not be better to just use nuclear weapons and sit out the consequences in their deeply-dug tunnels and bunkers once some line is crossed? Has either side acted in a manner so consistent and predictable that it reassures the other, and greatly reduces the possibility of nuclear use? The fact is that little is really known about the North Korean leadership’s state of mind. Nor can it be assumed that in the current age of relentless public spin, “fake news,” and the social media maelstrom, the nuclear decision-makers of this hermetically isolated regime correctly interpret what they are seeing and hearing about leaders on the other side.

Brinksmanship involving nuclear-armed powers, as on the peninsula, reflect the inherent risk of escalation that accompanies steps taken to preserve the credibility of the threat of nuclear weapon-use. With use postures unknown to those outside closed elites within their governments, and no uniform commitment to confining use to strictly retaliatory situations, the ingredients are in place for crises that can take the world to the nuclear brink. Such crises can take many forms. The U.S., for instance, sped up deployment of its Terminal High Altitude Area Defense (THAAD) system in South Korea in response to Pyongyang’s increased pace of missile testing, which in turn has resulted in redoubled North Korean testing and vocal opposition from China and Russia. Elsewhere, escalating tensions in disputed Kashmir in 2016 reportedly led Pakistan’s Defense Minister Muhammad Asif to threaten the use of tactical nuclear weapons against India.

Nuclear weapons programs as black boxes

For nuclear deterrence proponents, the maintenance of strategic stability hinges in part on the straightforward answers nuclear weapons provide to questions of “What deters? How much is enough? And what if deterrence fails?” Yet the presence of North Korea and the other second-generation proliferators undercuts the simplicity of the answers. The extreme opacity of the North Korean regime, for instance, highlights the challenge of capability assessment. Only in July 2017 did the U.S. Defense Intelligence Agency conclude that Pyongyang had developed a miniaturized nuclear warhead (a claim made in 2016), and there remains dispute as to whether its July 2017 test demonstrated possession of ICBM technology. Any incorrect or out-dated misconceptions about capabilities calls into question the applicability of defense and security postures — a critical blow to the supposed elegance of deterrence doctrine.

Indeed, the secrecy associated with nuclear weapons programs further hinders the predictability critical to the value of nuclear deterrence. Opacity may be sound logic from a national perspective — preserving both the security of a deterrent and the ambiguity central to use credibility — but it has the concurrent effect of increasing the possibility for escalation. Indeed, the likelihood of inadvertent or deliberate nuclear use is likely underestimated, considering the long history of (known) near misses, false alarms, and accidents, and in light of the rudimentary state of knowledge regarding the susceptibility of components to hacking and cyber-attack. While the U.S. and the Soviet Union hardly operated with perfect information during the Cold War, the multitude of new unknowns today — including a larger number of nuclear-armed states — throws additional wrenches into the environment.

The dearth of information extends beyond capabilities. Little is known about the laws and regulations North Korea has in place — if any — to preserve the safety and security of its stock-piled materials, even as it ramps up development and expands its activity across multiple sites. The case represents an extreme but not an exception, as the availability of such information varies significantly across possessor states. With the construction of a crude nuclear bomb identified as a primary risk scenario, and nuclear ambition expressed by terrorist groups like al-Qaeda and the Islamic State, threats of material theft and facility sabotage cannot be taken lightly. The information deficit thus undermines the viability of nuclear weapon-based deterrence both directly and indirectly — especially as the non-state threat demands its unnatural application.

Nuclear usability

The central paradox of nuclear deterrence rests in the rationale that it is “the very lethality of nuclear weapons that lessens the likelihood of their use sufficiently to make us safe.” There is no advantage to use given the inevitability of retaliation, as advanced by policymakers and theorists, and thus it follows states are reassured that nuclear weapons must not and therefore will not be used. Yet, as the credibility of the threat of use relies upon “risk, unpredictability, and extreme consequences,” states continue to be enhancing the possibility of escalation. Further, they appear to be lowering the very threshold for use — chipping away at the shared understanding of “unacceptable costs” key to the upkeep of nuclear deterrence.

Again, the North Korean case exposes the precarious logic of nuclear weapon-based deterrence. Its repeated and specific threats of use call into question whether the regime is constrained by the use “taboo.” The nature of its recent tests — emanating from multiple sites, with ranges that match those of U.S. bases in Japan and South Korea, and in the latest instances flying over Japan — coupled with an ever-improving capacity to weaponize its missiles add further cause for concern. With the Trump administration offering its own harsh rhetoric in response (a stark departure from predecessors), nuclear deterrence appears at risk of playing out to a catastrophic conclusion.

Yet nuclear deterrence proponents should be alarmed that nuclear-armed states are not merely normalizing the nuclear warfighting option with their rhetoric but with their practices and policies. Modernization programs widespread across possessor states have made these armaments more effective in locating and destroying targets, not just more credibly usable in a deterrent sense, but attractive for actual warfighting. Exacerbating this is the use of delivery systems — such as the air-launched cruise missiles maintained by the U.S., Russia, and France — that expand conventional and nuclear flexibility. Alarmingly, these program and military strategies are built on assumptions about the controllable nature of nuclear conflict and of the toxic, long-lasting radiation that would result.

Stepping back from the brink

Challenges to the predictability of nuclear deterrence upend the possibility that it can serve as a foundation for strategic stability much longer. They put unprecedented strain on the (fallible) human safeguards in place against nuclear use, making manifestly clear the need for fail-safes and mechanisms for de-escalation and prevention of catastrophic accident or misperception. Following the Cuban Missile crisis for instance, the two nuclear superpowers created a Moscow-Washington hotline. Yet half a century later, in a far more complex global environment, there remains a dearth of such dedicated communications channels and emergency hotlines beyond a bilateral basis. Even where such mechanisms exist, they have not been immune to political maneuvering: North Korea disabled its military hotline with Seoul in response to joint US-ROK military drills in 2013 and following the ROK suspension of cooperation at Kaesong in 2016.

The significance of such last lines of defense illustrates the volatility of crisis situations in the first place, and the need to preserve what meager stability can be gleaned through deterrence prior to reaching the brink. Information plays a key role, with the New Strategic Arms Reduction Treaty (New START) between the U.S. and Russia a potential model for multilateral information-sharing, for example on air-launched cruise missiles and delivery systems. The reduction of the operational status of nuclear-tipped missiles, the separation of conventional from nuclear stockpiles, or their command and control systems, and bans on entire classes of weapons (such as cruise missiles or short-range nuclear-capable tactical missiles) can reinforce the clarity that underwrites deterrence, lessening the possibility for escalation.

Still, risk reduction demands more than a lengthening of the fuse. Instead, it is essential to overturn the trend towards normalizing nuclear warfighting. Yes, the very norm of nuclear deterrence contains the idea that “there are circumstances so extreme that they would remove all inhibitions on nuclear use.” Yet, current rhetoric and modernization efforts help to expand the spectrum of “acceptable” circumstances. To reverse the trend, all nuclear-armed states should adopt no-first-use policies (in the vein of China and India), or eliminate launch-on-warning postures. More effective measures will require a reappraisal of nuclear deterrence in this day and age and its alleged benefits versus its risks, especially when other means of deterrence are available, such as precise conventional weapons and cyber.


The crisis on the Korean peninsula continues to loom. Six-Party Talks are long stalled; the long succession of UN sanctions has done little to slow the steady development of North Korea’s nuclear and ballistic missiles programmes. For nuclear deterrence proponents, the bleak picture provides a reaffirmation of the value of nuclear weapons. What else is to stop Kim Jong-Un from following through with his brazen threats? Why else would he pause before attacking South Korea, Japan, even the U.S., if not for the knowledge that retaliation is inevitable?

As argued, however, the case of North Korea underscores not the enduring logic of nuclear deterrence but its flimsiness. It is a microcosm of global nuclear risk, a logical consequence of the central role ascribed to nuclear weapons in the security landscape. As the fuse for nuclear confrontation burns ever shorter, the idea of strategic stability rooted in nuclear weapon-based deterrence appears increasingly shaky. The recent adoption of the Treaty on the Prohibition of Nuclear Weapons indicates a clear majority of states recognize the severity of the situation and see nuclear deterrence as a dangerous relic of the past — even as nuclear-armed states and their allies remain enmeshed in its logic.

Yet, there is common ground in re-evaluating these long-held beliefs on nuclear deterrence as a contribution to nuclear risk reduction. A focus on risk reduction has been an important point of policy convergence for the international community, and must remain so. Ultimately, the threat of escalation into nuclear conflict cannot be taken lightly, as the North Korean situation underlines. As former United Nations Secretary-General Ban Ki-moon said, there are “no ‘right hands’ that can handle these ‘wrong weapons.’”

John Borrie is the Chief of Research with the United Nations Institute for Disarmament Research (UNIDIR). Tim Caughley is retired; he was formerly Resident Senior Fellow at UNIDIR, Director of the UN Office of Disarmament Affairs in Geneva, and Deputy Secretary-General of the Conference on Disarmament. Wilfred Wan is a researcher with UNIDIR.

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