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Just as many dismissed the possibility of the Russian invasion of Ukraine in February, academics continue to assert a low probability that Russia will employ nuclear weapons in Ukraine. To be sure, there are many disincentives: the risk of escalation with the US and NATO; the likelihood of being isolated from the international community; and the uncertainty of whether a nonstrategic, tactical nuclear weapon (TNW) would indeed bring a desirable conclusion to the conflict. However, Vladimir Putin’s increasingly tenuous political and military position has reshaped TNW use into a legitimate recourse in his otherwise failing theory of victory. Moreover, flawed assumptions about US-NATO deterrence and Russian interest in TNWs have led us to severely underestimate the likelihood of Russia following through on nuclear escalation. Indeed, if current political and military trends continue, Putin would have compelling reasons to opt for TNWs, perhaps as soon as early 2023.
Winter is Coming: How TNWs Could Fit into Russia’s Theory of Victory
Russia’s immediate strategic outlook is ostensibly predicated on a winter-induced energy crunch compelling European nations to break from US leadership, withhold Ukrainian support, and perhaps even lift some sanctions. With Ukraine weakened, reinforced Russian troops would supposedly retake the initiative in 2023 and increase their negotiation leverage. However, this strategy is likely to fail and leave Putin desperate enough to resort to non-conventional methods of prosecuting and concluding the war. European leaders have already steeled their populations for lower energy consumption, stocked up on reserves, and signaled continued support for well-tailored aid to Ukraine. Even a difficult winter seems unlikely to alter European positions on the war, which many European countries now see as distinct from the question of energy management. In the long-term, European policymakers have prioritized independence from Russian energy supply, reducing the degree of leverage Putin will have in this domain should the conflict extend beyond this winter.
Meanwhile, on Ukraine’s battlefields, winter will harden the terrain and set ideal mechanized warfare conditions for which Ukrainian troops are already prepared. The Ukrainian 93rd Mechanized Brigade’s recent success against Wagner mercenaries and Russian forces in Kharkiv is illustrative of what we could see in the winter. Facing highly motivated and well-equipped Ukrainian counteroffensives, discombobulated Russian ground troops are relying on inadequate equipment, mercenaries, and relatively untrained reservists to hold disintegrating lines amid hostile populations. The result so far has been impressive, with Ukrainian forces liberating villages in the east from Kharkiv to the northernmost corners of Donetsk, and making significant progress toward Kherson to the south, where Russian forces appear poised to retreat east of the Dnipro. Although Putin’s partial mobilization has stabilized some Russian lines, Russian conscription cycles suggest that the next major flow of troops will not arrive until the muddy spring, setting the stage for renewed Russian offensives only when weather conditions for military activity in Ukraine are at their worst. Until then, Ukraine will have roughly three to four months to continue leveraging weather, terrain, resolve, and expertise to their advantage.
These developments hold serious implications for the potential use of TNWs, especially considering the enormous political investments Putin has already made at this stage of the war. The partial mobilization of 300,000 reservists extracted a tremendous political toll in a war which already places Putin’s political future on the line. As losses on the ground continue to mount, Putin faces a choice between the political costs of additional mobilizations or escalating to achieve victory by other means. This dilemma may lead Putin to choose an “escalate to de-escalate” approach, where TNW use would be expected to quickly induce negotiations favorable to Russia without the military and political costs of conventional fighting. Prior to the war, such a move had been disregarded by critics as inconsistent with Russian military doctrine. However, political pressure and military setbacks have allowed nuclear escalation to emerge as a viable solution to Putin’s dilemma. Recent intelligence reports indicate such conversations are already taking place within Russian decision-making circles.
By escalating to TNWs, Putin could expose limitations in Western resolve and bring about a “termination of hostilities on terms acceptable to Moscow.” The aim of employing TNWs would not be to achieve in material destructive terms what a conventional bomb could not, but rather to rapidly induce concessions, achieve political objectives, and preclude the Russian casualties that would otherwise result from attacking with conventional forces. The United States applied the same strategic thinking to end the Pacific War. By inducing fear and impressing the imminence of destruction among Ukrainian political leadership, a nuclear strike would serve as a psychological weapon leveraged to fulfill Putin’s political goals. Such an escalation would effectively hinge on the assumption that the United States and its allies do not have the political will to go tit-for-tat on nuclear escalation in Ukraine. Yet if Putin succeeds in exposing these limitations, he could capitalize on the unreliability of Western security assurances to Ukraine, initiate negotiations with compelling nuclear leverage, and use this leverage as a verified tool against future NATO and Western influence in post-Soviet countries.
While nuclear bluffs have been a consistent feature of Vladimir Putin’s war rhetoric, any assumption of bluff comes at the cost of ignoring Putin’s political and military realities. Previous “red lines” against Finland’s bid for NATO membership, US provisions of long-range rocket system, and strikes on Crimea were drawn in the early phases of the war, when Russian troops still held much of their initial gains. Having now been forced into partial mobilization amid sizable losses, Putin faces a radically different strategic landscape today than he did six months ago. As Russian lines continue to recede and domestic political turmoil grows, calling Putin’s “bluffs” will become an increasingly risky endeavor. Equally critical is the fact that in the absence of a politically viable, conventional option, nuclear escalation may be Putin’s best and only alternative short of surrender.
Challenging Assumptions on Deterrence and Russian TNW Use
Although TNWs may become a strategically viable instrument for Putin, a great deal of skepticism persists among academic circles and military analysts on the question of whether Putin is willing to assume the risks of nuclear escalation. Unfortunately, such assessments suffer from a fundamental overconfidence in the influence of US-NATO deterrence.
The prevailing belief that Putin would be deterred by potential US or NATO retaliation must properly contend with whether or not Putin himself is likely to find the threatened costs of Western retaliation to be both unacceptable and credible. Weighing perceived costs is essential: if Putin decides that the political and military costs of refraining from using TNWs are greater than the potential costs of retaliation, Western deterrence is unlikely to hold.
Unfortunately, if Russia continues to experience devastating military setbacks, Putin may attach existential costs to foregoing TNW use. Any assessment of Putin’s cost-benefit analysis must take full stock of the degree to which Putin has risked his entire political life and Russia’s geopolitical standing on the war’s outcome. Putin’s own political investment so dramatically raises his costs of defeat that even the strongest assurances of retaliation may be insufficient to deter him. Beyond his personal interests, Putin has also framed the war in Ukraine as a fight to reassert Russia’s great-power status and sphere of influence, striving to revive the prestige of the Soviet era. These geopolitical stakes further increase the costs of losing and could elevate the risks Putin might be willing to accept to avoid defeat. Putin’s definition of these costs may ultimately prohibit effective deterrence, regardless of US and NATO signaling.
However, in addition to Putin’s high tolerance for risk, the credibility of US deterrence is a major issue. President Biden’s ambiguously worded comments on potential retaliation do little to suggest the United States is prepared to act beyond military and economic aid and meet nuclear force with nuclear force. To the contrary, Biden only asserted that Russia would become a “pariah,” with the scale of the United States’ response depending on the extent of Russian action. Such pariah status may be achieved in the West as long as the cohesion of the US-European coalition holds, but Russia’s natural resources, expansive geographic presence, and closer relationships with China, India, Iran, and other Middle Eastern partners make it unlikely that Russia ever becomes as isolated as North Korea.
Moreover, the credibility of US retaliation itself may be undermined by the outcome of the November midterms. If Republicans regain control of Congress, Putin would have substantial reason to anticipate weaker American interest in the war due to significant Republican opposition to continuing aid at the existing level. This potential weakness in US posture highlights the comparatively non-vital place Ukraine holds in American global interests relative to Russia’s and may embolden Russia to exploit that disparity. If Putin were to order the use of a lower-yield TNW (i.e. a blast of less than 10 kilotons, 50% smaller than the bomb used on Hiroshima) on an infrastructure target resulting in minimal civilian casualties, the relatively constrained nature of the strike could offer President Biden a potential “off-ramp” to double down on economic measures but avoid military or nuclear escalation. This tactic could become more tempting if Republicans retake Congress or the economy goes into recession, both of which would sap domestic political interest in a tit-for-tat retaliation.
Proceeding with Caution
Putin has made considerable political investments only to achieve remarkably poor results on the battlefield. However, the winter stages of the war have yet to play out and are certainly not assured to fully reverse Russia’s gains. Even if Ukrainian forces continue to advance, it is essentially impossible to know the exact point at which Putin would perceive TNWs to be necessary over non-nuclear escalation. This uncertainty renders the option of calling Putin’s bluffs particularly dangerous as Ukraine continues to repel Russian lines. In the face of Ukrainian advances, Putin could potentially threaten the imminent use of TNWs in order to extort desirable concessions from Ukraine and its Western partners. Given the anticipated wave of reinforcements, Putin likely expects to renew conventional offensives in the spring, suggesting that Ukraine’s success over the winter would need to be dramatic for Putin to reach this level of urgency in the next six months. Even so, Putin’s bluffs will likely need to be called at continuing intervals in the conflict, and persistent Ukrainian progress will render this a challenging task.
An undiscussed assumption in this article is the extent of Putin’s micromanagement of military operations. Early stages of the war pointed to his active involvement in tactical decision-making, suggesting a disregard for the opinions and authority of his military advisors. This civilian-military leadership dynamic, along with the authoritarian nature of the regime, provide grounds to consider Putin the ultimate decision-maker in the Kremlin. Nonetheless, Putin’s current management of the internal discussion over the use of TNWs and where senior military officials stand on the question are essential areas of inquiry to pursue. Answers to these questions could provide vital insight into the timing, targeting, and thresholds Russia might consider as it weighs its options.
In the meantime, any persisting doubts about the possibility of nuclear escalation must be carefully reconsidered. Although the United States and its allies certainly possess the resources to inflict proportionate economic and military costs, it is unclear whether they can credibly signal their resolve to respond accordingly. Equally important, Putin’s cost-benefit analysis may predispose him to undertake the greater risks, regardless of the credibility of Ukraine’s allies. It is essential that analysts and policymakers meaningfully consider these factors in their assessments moving forward in order to better inform strategic planning.