It’s slightly deceptive to say that Ukraine once wielded the third biggest nuclear arsenal in the world, but it’s also true. When Ukraine became independent in 1991, it inherited thousands of nuclear weapons mounted on intercontinental ballistic missiles, and on cruise missiles strapped to strategic bombers; the Nuclear Threat Initiative also reports that it had an unknown number of tactical nuclear weapons on its territory. But it only exercised command and control over a small fraction of the arsenal, so its nuclear deterrent lacked credibility. It’s worth wondering, though, if Ukraine had developed an indigenous nuclear weapons program on top of the one it inherited from the Soviets, would Russia have been able to seize and occupy the Crimean Peninsula as easily as it did on Saturday?
Ukraine’s decisions to pursue multilateral denuclearization and to join the Nuclear Nonproliferation Treaty as a non-weapons state were met with nearly universal support in the West. Russia, of course, was also pleased. John Mearsheimer, however, registered his dissent in a 1993 article in Foreign Affairs. “A nuclear Ukraine makes sense,” he suggested. “It’s imperative to maintain peace between Russia and Ukraine…Ukrainian nuclear weapons are the only reliable deterrent to Russian aggression.” Mearsheimer argued that a Ukrainian nuclear deterrent would be crucial for peace between the two countries—and European stability—after the Cold War. The threat of full-scale war between Russia and Ukraine now looms over the crisis in Crimea, and Mearsheimer’s arguments merit reexamination.
Would nuclear weapons have stabilized, or deepened the Ukrainian political crisis? Would they have deterred Russia’s conventional forces? Answering these questions is more than a purely counterfactual exercise; it’s important for understanding the value of nuclear arsenals for state sovereignty and has clear implications for the future of the nonproliferation regime.
I argue that a Ukrainian nuclear arsenal would not necessarily have prevented Russian aggression in Crimea, but that it definitely would have deepened the political crisis. Nuclear weapons would have raised the stakes of Ukraine’s tumultuous transition, and they would have hardened deposed President Viktor Yanukovich’s resolve to stay in power. Also, nuclear weapons may not have deterred Russia’s seizing the Crimea—as evidenced by the multiple border skirmishes between India and Pakistan—but they would have seriously reduced the likelihood that Russia invades Eastern Ukraine. Finally, decisions regarding the use of nuclear weapons may not have been governed by caution and restraint, because the Crimean crisis has escalated so quickly, and Ukrainian civil-military relations are clouded by transitional uncertainty and defection.
I assume, as Mearsheimer did, that Ukraine would have been able to develop and competently retain a secure second-strike capability. Its civilian nuclear program is sufficiently robust that—even if it transferred the cache of highly enriched uranium it inherited from the USSR—it could have harvested enough weapons grade plutonium from chemically-reprocessed, spent nuclear fuel for a survivable arsenal. I also assume that despite initial opposition to Ukrainian nuclear retention from Yeltsin’s Russia, the two nuclear neighbors would have enjoyed normalized relations to date. France and Great Britain are also historical rivals that find a way to possess nuclear arsenals and share normal relations in the same region.
If President Yanukovich, as Commander and Chief of the Ukrainian military, had controlled a nuclear arsenal, would he currently be deposed? I suggest two possible scenarios, neither of which is attractive. Presidents are always loath to relinquish office under duress, and this sentiment is likely deepened by the prospect of transferring control of nuclear weapons to political rivals or revolutionary forces. So, it’s not a stretch to believe that Yanukovich’s resolve to retain power would have hardened. In this scenario, the political violence, repression, and clashes in Kiev and other parts of Ukraine may have persisted and intensified, and Yanukovich may have used the military more aggressively to quash the protests.
Alternatively, Yanukovich may still have fled, fearing for his family’s safety (as well as his own), and nuclear weapons would have raised the stakes of political transition considerably. The acting government, which may have reduced state capacity due to key military defections and limited sway over the vast patronage networks that Yanukovich wielded, would have to account for a nuclear weapons infrastructure. Pakistan is the only other nuclear weapons state that has endured tumultuous and violent political transitions, and offers an unexpected (to me, at least) glimmer of hope. Last September marked the first time that a democratically elected Pakistani president— Asif Ali Zardari—completed his term in office. However, as Feroz Khan writes, “despite domestic instabilities and rough political transitions, by and large the control of the [Pakistani] nuclear program has remained unaffected.” There is a chance, then, that command and control of Ukrainian nuclear weapons would not have been seriously affected by Yanukovich’s flight and the uncertain transition to an acting government. Still, few observers would argue that the world needs more nuclear weapons states in the mold of Pakistan.
Moving on to Mearsheimer’s central concern, would a Ukrainian nuclear deterrent have prevented Russian aggression in Crimea? Mearsheimer wrote that nuclear weapons are a “powerful force for peace,” and that they were a “principal cause” for the absence of interstate war in Europe during the Cold War. Furthermore, he argued, “an aggressive Russia could not dismiss the Ukrainian nuclear threat.” I don’t intend to engage in the overarching debate on the peacemaking effects of nuclear arsenals—though in the interest of full disclosure, I sympathize with both Mearsheimer’s view as well as John Mueller’s belief in nuclear weapons’ “essential irrelevance.” Instead, my argument is narrower in scope. A Ukrainian nuclear deterrent would not necessarily have prevented Putin from seizing the Crimean Peninsula, but it would have drastically reduced the likelihood that Russian forces stage an invasion of Eastern Ukraine. That is, I agree with Mearsheimer that nuclear weapons can serve as a powerful guarantor of state sovereignty, but I argue that they are less effective at deterring lower levels of violence, such as border skirmishes. India and Pakistan’s recent experience clearly demonstrates this. Both countries conducted nuclear tests in 1998, which were followed in short order by the Kargil War. In that case, an Indian secure second-strike capability did not prevent Pakistani troops from crossing the Line of Control. Since then, there have been a number of smaller skirmishes and standoffs, which nuclear weapons have failed to deter.
Yes, there is a possibility that Putin would have refrained from taking the Crimea in the face of a Ukrainian nuclear deterrent, but it is far from ironclad. If Putin had dismissed the Ukrainian nuclear threat and taken the Crimea anyway, I believe that a subsequent march toward Kiev would be far less likely than currently feared. Of course, this logic is predicated on the ability to control military escalation so that it does not result in conventional war or a nuclear exchange. Mearsheimer wrote that Russia would exercise caution in its war-footing vis-à-vis a nuclear Ukraine, because, “there is always the possibility that nuclear weapons might be used inadvertently or accidentally in the course of a conventional war.” This reinforces my belief that the probability of a full-fledged invasion of a nuclear Ukraine would be vanishingly small. However, there is no standard by which the military action in Crimea can so far be classified as a conventional war, and Putin could believe that preventing escalation to conventional or nuclear war is in his control. Therefore, it’s possible that Putin would seize the Crimea from a nuclear-armed, transitional Ukrainian government, believing that it would not risk national suicide in order to keep the territory from becoming Russian property. Unfortunately, when nuclear weapons are involved, control over escalation can be illusory. While Mearsheimer argued that this would prevent all forms of Russian aggression against Ukraine, I counter that Russia might still engage in military actions short of war, but that the added variable of nuclear weapons would make the consequences of unforeseen escalation potentially cataclysmic. The speed with which the crisis in Crimea has unfolded—against the backdrop of key military defections and the political uncertainty of a chaotic transition of power—raises the possibility of the inadvertent launch of nuclear weapons.
The ongoing crisis in Ukraine provides an opportunity to draw lessons about the importance of nuclear weapons for presidential power, state sovereignty, and territorial integrity. I have argued that if Ukraine had developed a secure second strike capability after its independence in 1991, then Yanukovich still might have been deposed, but that he would have ordered more intense levels of political violence and brutal repression. In democratic countries, then, nuclear weapons do not automatically guarantee the political survival of embattled leaders. Also, in contrast to Mearsheimer, I maintained that a Ukrainian nuclear deterrent would not necessarily have prevented Russia from seizing the Crimean Peninsula, but that it would have served to increase the consequences of unintended escalation to unacceptable levels. I agree with Mearsheimer that a survivable nuclear arsenal is a powerful last resort for protecting state sovereignty and regime survival, but I do not believe that it protects territorial integrity as stalwartly as Mearsheimer’s arguments suggest. So, as the world anxiously hopes for a peaceful resolution to the crisis in Crimea, I am grateful for the multilateral efforts in the 1990s that successfully denuclearized Ukraine.
 Mearsheimer, John J. 1993. “The Case for a Ukrainian Nuclear Deterrent.” Foreign Affairs, Vol. 72, No. 3, p. 50-51.
 Mearsheimer, 1993, “Ukrainian Nuclear Deterrent,” p. 57.
 Mueller, John. 1988. “The Essential Irrelevance of Nuclear Weapons: Stability in the Postwar World.” International Security, Vol. 13, No. 2 (Autumn), pp. 55-79.
 Mearsheimer, 1993, “Ukrainian Nuclear Deterrent,” p. 57.