Nuclear The Future of Responsible Nuclear Statecraft: New Era, Old Realities

Avery Goldstein is the David M. Knott Professor of Global Politics and International Relations at the University of Pennsylvania. This article is a product of a Perry World House workshop on “The Future of Nuclear Weapons, Statecraft, and Deterrence after Ukraine”, which took place on April 4, 2023. This workshop was made possible in part by a grant from Carnegie Corporation of New York.

Deteriorating US-China relations and Russia’s decision to launch a war against Ukraine in early 2022 have reawakened concerns about the danger of war between nuclear-armed great powers. For some, these concerns reflect the belief that the current nuclear era is more dangerous than its Cold War predecessor, due to rapid advances in technology. Is the danger of nuclear war today greater than that faced in the past? This article addresses this question and illustrates key points with reference to the war in Ukraine and the ongoing tensions in the Taiwan Strait. In so doing, it provides the basis for conceiving standards for responsible nuclear statecraft. The analysis and its normative inferences suggest that the greatest challenge to responsible statecraft, both at present and for the foreseeable future, is a failure to fully grasp the enduring realities of the nuclear age that emerged in the first decades after 1945, and whose overriding importance endures. Whatever the reason for this failure, it is facilitating the zombie-like return of dubious and potentially dangerous ideas about military force in confrontations between nuclear-armed great powers.

Dramatic Change, Important Continuity

Several technological advances in the twenty-first century have altered the nuclear landscape. Developments in surveillance and tracking, terminal guidance, hypersonic missiles, and maneuverable platforms to deliver warheads are increasing the expected effectiveness of offensive strikes against an adversary’s nuclear weapons. Improvements in ballistic missile defense are increasing the effectiveness of defenses against an adversary’s nuclear strikes. And the emergence of sophisticated electronic, cyber, and artificial intelligence technologies promise more effective command and control over such offensive and defensive systems, as well as new means to disrupt or destroy an adversary’s ability to conduct its military operations.

These notable changes are key reasons why many see the current and future nuclear era as dramatically different from the past. They are invoked to argue that it is now possible to embrace strategies for the use of nuclear weapons that were not feasible before. Such technological advances, however, have not altered the continuing importance of two intertwined features of the nuclear revolution that cast doubt on their strategic significance: the robustness of nuclear deterrence and the remaining risk of nuclear conflict.

First, nuclear weapons made deterrence remarkably easy, because with nuclear weapons its requirements are simple, straightforward, and relatively affordable. They provide an unprecedented capability to confront an adversary with the fear that military conflict could quickly result in horrifying damage to its country. A nuclear-armed state does not need to convince its adversary that it will win a military struggle, or even that it will certainly inflict catastrophic nuclear punishment in retaliation. It is only necessary for a state to ensure that its adversary remains uncertain about whether it can escape unacceptable damage to its most important centers of political and economic life do not yet offer a clear path to altering this reality of the nuclear age, the paralyzing fear that makes deterrence effective. Technological advances will likely continue to improve the ability to destroy a large fraction of a state’s retaliatory forces and improve the ability to defend against the smaller number of retaliatory forces that might survive such an attack. But with nuclear weapons in play, even a diminished chance of suffering retaliatory damage is politically more important than the growing impressiveness of offenses and defenses.  What matters most is the horrific damage that can be inflicted by the few weapons that remain, not the ever-larger fraction that one can neutralize.

Second, although nuclear weapons make deterrence much easier and thereby dramatically reduce the temptation to initiate nuclear war, they do not eliminate that catastrophic possibility. Indeed, it is the very possibility of catastrophe that underpins the uncertainty essential for deterrence to work in the nuclear age. It is essential because, as strategists have noted since the 1950s, once a nuclear state faces a nuclear-armed adversary, it is nearly always irrational to choose to launch strikes while the possibility of retaliation exists. Such rationality, however, is not an airtight guarantee against nuclear conflict. Danger remains because states that will not rationally choose to initiate a nuclear war may yet rationally choose to risk a nuclear war. Why might they take that risk? Ironically, perhaps, policymakers contemplating military conflict may believe that nuclear considerations can be set aside, precisely because no rational leader would ever dare use these weapons of mass destruction as long as mutual deterrence prevails. This belief reflects what strategists have labeled the “stability-instability paradox.” It is dangerously misleading, however, to interpret the paradox as a claim that mutual deterrence makes it safe for nuclear armed states to fight limited wars. On the contrary, it makes such limited wars more dangerous than ever. Because the use of nuclear weapons remains possible, limited wars will be shadowed by the risk of catastrophic escalation. During a limited conflict, it is unlikely that either state would choose nuclear escalation. But if either grows frustrated with the course of the war or especially if either believes its vital interest are in jeopardy, then it may be tempted to threaten nuclear escalation to coerce its adversary. If it does, then it is likely to loosen its normally reliable peacetime controls over nuclear forces to send a more credible signal, and its adversary is likely to do the same to preserve the credibility of its retaliatory threat. Such actions open an array of pathways through which escalation can lead to the nuclear disaster neither side would have rationally chosen.

Ukraine and Taiwan

Ukraine

The constraining effects of nuclear weapons that induce caution, as well as the continuing danger of nuclear conflict, have both been evident in the Ukraine war. At first blush, one might wonder if Vladimir Putin’s incautious decision to invade Ukraine casts doubt on the constraining effect of nuclear weapons, especially in light of the dangerous war it triggered. His brazenness, however, rested on confidence that Russia would not be directly engaging the militaries of the US and its NATO allies. President Joseph Biden, after all, had explicitly stated that he was sticking with the US policy – in place since 2014 under President Barack Obama – that ruled out direct American confrontation with Russia in Ukraine, most notably because of the nuclear escalation risks the US would face if it intervened. Putin, therefore, could set aside the risk of nuclear escalation prior to the attack, especially since he mistakenly expected a quick victory before the US might reconsider its policy. In the event, Putin’s blitzkrieg failed. At that point, nuclear fears began to play their expected role in shaping the choices that both nuclear-armed great powers have been making.

Fearing unpredictable escalation that might result from war with a nuclear adversary, the US decision to assist Ukraine has been implemented cautiously and within limits. Russia has manipulated this fear with nuclear saber rattling that reminds the US of the risks it could face. Because they are reminders of what escalation means when nuclear weapons are in play—the reality that makes deterrence relatively easy—even vague threats have been taken seriously. But Russia, too, has been constrained by the fear of escalation. Despite the role of tactical nuclear weapons identified in its doctrinal writings, a militarily stymied Russia has predictably eschewed their use in Ukraine. Instead, when Moscow rattles its nuclear saber, it does so with reference to ensuring the survival of the Russian regime against external challenges, a contingency for which the credibility of its nuclear deterrent has never been in doubt. In addition, the US has made its own vague nuclear threats, reminding Russia of the grave consequences that it would face if it were to use nuclear weapons for any reason other than dealing with challenges to the survival of Russia itself. The American stance, then, simultaneously acknowledges the credibility of Moscow’s nuclear threats to deter existential challenges to Russia, while also dissuading the use of tactical nuclear weapons on the battlefield in Ukraine. Finally, fear of the escalation risks that would follow from direct confrontation between nuclear-armed great powers may go a long way towards explaining what is otherwise puzzling—Russia refraining from attacks on the supply lines beyond Ukraine, through which the US and its allies are providing crucial military support for Kyiv’s war effort.

As noted above, however, nuclear constraints induce caution but do not eliminate nuclear danger. A state frustrated in war may be tempted to manipulate the fear of nuclear escalation to coerce its adversary. At that point, the importance of the conventional fight on the battlefield gives way to the test of nuclear brinkmanship, in which each side’s willingness to run risks turns on the interests it has at stake. As the war in Ukraine drags on, it is not hard to imagine the US and Russia taking steps that at some point transform the current war into a test of wills in which nuclear weapons shape the outcome. Under those circumstances, it seems likely that it will be difficult for the US to convince Russia that it has vital interests at stake that make it as willing as Russia to near the brink of nuclear disaster over the fate of the Donbas or Crimea. If so, while many have voiced disappointment with the cautiousness of the Biden administration’s military backing for Ukraine’s fight to reclaim its territory from Russia, such caution arguably serves Ukraine’s interests as well as those of the US. Limiting US military support minimizes the risks of escalation that would transform a difficult conventional war into a great power nuclear confrontation more likely to favor Russia.

Taiwan

Deepening US-China tensions over the fate of Taiwan are setting the stage for another great power confrontation shadowed by the nuclear sword of Damocles. Because of four key differences to the context in Ukraine, the fraught realities of the nuclear era would be even more relevant in the case of a US-China crisis or conflict in the Taiwan Strait.

First, unlike Russia when it decided to attack Ukraine in 2022, China has fully expected direct US intervention if it moves against Taiwan since at least the mid-1990s. This clear expectation has shaped China’s contingency planning for the use of military force against the island. Second, in contrast with Russia’s expectation in 2022, continued US intelligence and military operations in the region, as well as the challenges of an amphibious invasion, mean that leaders in Beijing cannot count on a quick attack resulting in a fait accompli that secures its objectives. Instead, China must anticipate the steps they will take once the US responds and a crisis or conflict intensifies.

Third, unlike Ukraine, because a confrontation would directly engage the military forces of the US and China, the nuclear specter would loom earlier and larger in a confrontation over Taiwan, a context where both sides have vital interests at stake. China and the US both know that the other will be prepared to run substantial risks of escalation to protect its interests. China’s vital interest at stake is defense of its territorial and political integrity, consistently defined by China as including sovereignty over Taiwan, making the island’s future status a litmus test for regime legitimacy in the PRC. This is very different to Russia’s stance on Ukraine after 1992. The US vital interest at stake is the credibility of its public commitment to respond to challenges from a richer and more powerful China in the Indo-Pacific, most importantly to preserve the credibility of its commitment to key allies in the region. For both China and the US, interests greater than the intrinsic economic or military value of the island itself are at stake in Taiwan. These stakes continue to rise as domestic politics in both China and the US now encourages tough talk on the Taiwan issue and favors stronger military preparations.

Fourth, unlike Ukraine, because both sides believe they have vital interests at stake in the Taiwan Strait, they are more likely to be willing to raise the risk of nuclear escalation, setting the stage for especially dangerous brinkmanship. With neither side having a clear advantage in the balance of interests, both may cling to the belief that they can prevail in a war of nerves and continue upping that ante. Each such step increases the risk of actions that result in a nuclear conflict that neither side wants, and that neither side originally intended to initiate.

These features of a prospective US-China confrontation in the Taiwan Strait provide reason to worry that it would prove more dangerous than the war in Ukraine, and would court a greater risk of nuclear disaster. Indeed, given the high stakes, the directness of confrontation and the likelihood that brinkmanship will be accompanied by US-China military engagements, such a confrontation may even prove less amenable to peaceful resolution than the October 1962 Cuban Missile Crisis. Confrontation and conflict in the Taiwan Strait would see the US and China test the robustness of nuclear deterrence and court risks that more clearly increase the possibility that they will use their most devastating weapons. Analyses of prospective US-China military crisis or conflict in the Taiwan Strait that ignore this nuclear dimension omit what is likely to be most important.

Responsible Statecraft in the Nuclear Era

The persistent dangers of great power nuclear conflict, despite the enduring effectiveness of deterrence in Europe and Asia, suggest four criteria for responsible statecraft in the nuclear era.

First, given the low bar for deploying nuclear forces that suffice as a frightening deterrent, responsible statecraft avoids wasteful arms racing as opposed to the modest investments necessary to disabuse adversaries of the fantasy that they can eliminate the risk of horrifying retaliation. The opportunity costs of investing in more than a reasonably redundant retaliatory capability include forgoing investment in the domestic welfare of one’s citizens and sustaining the civilian foundation for those military capabilities that are useful for coping with external threats.

Second, because of the unavoidable risk that confrontations between nuclear-armed states may entail brinkmanship and a small but real possibility of unprecedented disaster, responsible statecraft requires an emphasis on diplomacy to head off confrontations and the dangerous crises that can result. Such an approach means strengthening deterrence, which requires balancing efforts to ensure the credibility of military threats with efforts to assure adversaries that their restraint will not be exploited.

Third, because it is unlikely that even the best efforts by the most sincere leaders of countries with genuinely conflicting interests can avoid all crises, responsible statecraft requires preparing to manage those crises that prove unavoidable. Such preparations again require more than military readiness. They require a focus on establishing reliable means to limit the risks of crisis instability that portend a slide from confrontation to the use of force that courts disastrous nuclear escalation.

And fourth, because crises may yet occur and the mechanisms of crisis management may falter when the willingness and ability to control the use of force erodes as conflict begins and casualties mount, responsible statecraft requires proactively addressing the challenges of ending the fighting as quickly as possible. The primary purpose should be to improve the chances for ending military conflict before any nuclear weapons are used, but it is also crucial to improve the prospects for terminating the use of nuclear weapons if they are used and a ceasefire remains viable.

Alas, with today’s most consequential nuclear states in mind, there is not much reason for confidence that considerations of responsible statecraft in the nuclear era are driving policy. This is clearest in the more troubling case of the United States and China, who are falling short on all four dimensions:

Investment in nuclear arsenals? Both countries remain focused on strategically dubious comparisons of the size of their nuclear arsenals, rather than the sufficiency of their retaliatory clout, a focus that is encouraging wasteful arms racing.  Both China and the US are undertaking nuclear modernization driven by China’s fear that it is badly outgunned and by the US fear of China catching up in the number of warheads and its deployment of delivery systems that will reduce the current US ability to destroy a large fraction of China’s arsenal and defend against what remains.

Diplomacy to avoid crises? Neither country is giving sufficient attention to crisis avoidance. Both are instead focused on military investments and actions, including air and naval operations in close proximity to one another, as part of their efforts to strengthen deterrence by making threats more credible. But with little attention to credible assurances that the adversary’s restraint will not be exploited, such military measures risk provoking the crises they are intended to forestall.

Crisis management? Although the US and China have established some channels of communication for crisis management over the past three decades, these are not well developed and, more importantly, they have repeatedly failed to serve their intended purpose when most needed, at moments when incidents have increased the danger of military conflict. These failures appear to have resulted mainly from China’s unwillingness to respond promptly to US contact. Whatever their cause, these experiences likely mean that the US now sharply discounts the reliability of existing channels for managing crises with China. This disturbing reality now appears to be further complicated by China’s recent rejection of US calls to improve channels for crisis communications as part of an effort to establish “guardrails” against inadvertent conflict, something that Beijing worries could embolden a US less concerned about the risks it will face if it confronts China.

Conflict termination? The failure to sufficiently attend to the task of avoiding crises and preparing to manage those that prove unavoidable bodes poorly for the prospect of quickly terminating conflicts that will be shadowed by the risk of nuclear escalation. More likely, ending military hostilities will depend on tacit bargaining, relying on actions to send messages to the adversary. Such signaling has always been an error-prone, unreliable approach to communication in the fog of war. One can only hope that the extraordinary stakes of nuclear conflict provide leaders with unprecedented incentives that quickly clarify the consequences of ignoring signals to end military hostilities and to avert the worst, knowing that in the nuclear age the worst takes on an entirely new meaning.

The statements made and views expressed in this article are solely the responsibility of the author.