Nuclear Overtones in the Russia-Ukraine War

June 2022
By Manpreet Sethi

Nuclear weapons today occupy center stage in an unexpected theater in Europe. The conflict between Russia and Ukraine has drawn attention to these weapons of mass destruction and the alarming possibility of their use in a manner that had mostly been forgotten. When the Cold War ended more than three decades ago, it was not anticipated that the threat of nuclear weapons use would make such a comeback. South Asia and the Korean peninsula were considered the more likely nuclear flashpoints, not Europe.

The remains of a school in Kharkiv, Ukraine, that was destroyed during fighting between Ukrainian and Russian forces on May 24. (Photo by John Moore/Getty Images)More than two months have elapsed since the start of the conflict. Although the actual fighting is taking place between nuclear-armed Russia and non-nuclear Ukraine, the threatening shadow of the nuclear weapons possessed by the United States and NATO is palpable. Since the Cuban missile crisis in 1962, this is the first real engagement between the United States and Russia where they are indirectly yet directly involved. Millions of lives have been disrupted, and several thousand people have died. This is an irreparable and inconsolable human loss.

There also will be long-lasting implications for states, whether possessing nuclear weapons or not, as to how these capabilities are perceived in the future. This experience has created profound nuclear challenges, but also offers some opportunities for reducing nuclear risks.

Nuclear Challenges

One immediate concern is the manner in which nuclear Russia has used force against non-nuclear Ukraine. A popular view emerging internationally is that Russia exploited its nuclear status to invade its neighbor and that its nuclear weapons, in effect, gave it the immunity to wage a war against a non-nuclear-weapon state.

This perception raises the stock value of nuclear weapons and could lead a non-nuclear-weapon state to reexamine its security requirements, especially when it experiences hostile relations with countries that possess nuclear weapons. It will have implications for how a non-nuclear-weapon state evaluates the worth of negative security assurances provided to it by the nuclear-weapon states. Despite such assurances being made to Ukraine in the 1994 Budapest Memorandum by the United States, the United Kingdom, and Russia, for instance, Russia has used the threat of the potential use of nuclear weapons as a way to deter Ukraine from soliciting and receiving outside support. This episode raises the possibility of similar instances of nuclear coercion against additional non-nuclear-weapon states, which, in turn, could lead these states to acquire their own nuclear weapons to fend off nuclear-armed adversaries.

A second challenge arises from the heightened risks of nuclear use when two nuclear-armed states engage in conventional war with each other. During the Cold War, it was generally assumed that, in case of a direct conflict between two countries with nuclear weapons, presumably the United States and the Soviet Union, the fighting would turn quickly into a nuclear exchange. As a result, the planning process in both countries shifted to the realm of nuclear war-fighting. The size and structure of the U.S. and Russian nuclear forces, targeting strategies, and civil defense measures were constructed with the inevitability of a nuclear war in mind. Little attention was paid to containing a war at the conventional level.

Fortunately, incidents of direct military engagement between nuclear-armed states were few. The only direct conflict during the Cold War between the Soviet Union and the United States took place in 1962 over Cuba, and a direct military clash between the Soviet Union and China took place over the Ussuri River in 1969. All other confrontations between nuclear superpowers were fought through their proxies in third countries that were themselves non-nuclear. This record, not surprisingly, reinforced the thinking among scholars and political leaders that nuclear deterrence averts war between nuclear-armed nations. Tomes have been written about how the presence of nuclear weapons induces nations to be prudent and to establish “tools for crisis management to reduce the prospect of the outbreak of unintended warfare, either nuclear or conventional.”1 Such a belief is also responsible for the positive spin around nuclear weapons as keepers of stability and peace between nuclear-armed nations and hence against the case for nuclear disarmament.

Interest and concern about the possibility of conventional wars that could be fought between nuclear-armed states picked up after India and Pakistan tested nuclear weapons in 1998. Given their historically troubled relationship and geographical contiguity, the possibility of conventional war within this nuclear shadow presented a significant new challenge. The West rushed to provide Islamabad and New Delhi with “nuclear learning” from its experience. Over the years, India and Pakistan have found ways of navigating the narrow space of conventional military operations against the backdrop of their nuclear weapons. Nevertheless, the risk of escalation can never be obviated.

The experience of Southern Asia, a term used to define the nuclear dynamics among China, India and Pakistan, underscores that when caught in a direct confrontation, nuclear-armed states, irrespective of their doctrine or apparent nuclear bluster, are cognizant of the consequences of intentional use and the risks of inadvertent use of nuclear weapons. Therefore, leaders take conscious measures to avoid risks and are forced to do two things: show high tolerance for their adversary’s military and political actions, and moderate the use of their own military capability to remain below the other side’s perceived nuclear threshold. A former Indian defense minister made this observation after the nuclearization of South Asia: “Nuclear weapons did not make war obsolete; they simply imposed another dimension on the way warfare was conducted…. [C]onventional war remained feasible, though with definite limitations, if escalation across the nuclear threshold was to be avoided.”2 As history has shown, nuclear-armed states of all hues are compelled to impose constraints on the use of their conventional military forces to avert raising the level of the crisis.

When India fought the war with Pakistan in 1999 over the Kargil district that had been clandestinely occupied by Pakistani army troops disguised as mujahideen, the Indian Air Force was instructed to operate without crossing the Line of Control, which divides the Indian- and Pakistani-controlled parts of Kashmir. Air operations to evict the intruders were conducted in a constrained space in order to avoid any chance of provoking Pakistan into expanding the conflict, thereby risking nuclear escalation. In more recent times, India’s response to continued cross-border attacks from Pakistan have taken the form of short, swift surgical strikes, as in 2016, or carefully calibrated air attacks, as in 2019. These operations have been crafted by India to punish without exploiting the full force of its conventional military capabilities. Pakistan’s retaliatory attacks also appear to have been prudently tailored to keep escalation in check.3

A similar pattern seems to be emerging in the Russian-Ukrainian conflict, where in order to steer clear of the specter of nuclear escalation, both sides are moderating their military actions. The United States and NATO have refrained from undertaking any overtly provocative actions. The Ukrainian demand for help in imposing a no-fly zone has been rejected. The United States cancelled a scheduled test of an intercontinental ballistic missile and refused to raise the alert levels of its nuclear forces despite Russian President Vladimir Putin’s threats and order to put his nuclear forces on somewhat higher alert. The objective of these Western efforts has been to avoid any action that could be misread by Moscow as a provocation.

Meanwhile, Russia has had to tolerate a certain level of arms and ammunition transfers to Ukraine. Even a strategic blow such as the sinking of the Russian flagship Moskva or reported high casualties among Russian troops have been absorbed. Despite the nuclear brinksmanship suggested when Putin threatened consequences “such as you have never seen in your entire history,” concerns about the use of nuclear weapons to redeem losses on the ground appear farfetched. This is true even though the Russian leadership has not hesitated to draw attention repeatedly to nuclear weapons, whether by testing a Sarmat missile on April 20 or reiterating the threat of “unpredictable consequences” if heavy arms were supplied to Ukraine by Western powers. Indeed, keeping the nuclear threat in the news is part of the Kremlin’s nuclear strategy of deterrence.

As it appears now, the war could progress in slow motion indefinitely until both sides can find an off-ramp that allows them to avoid the appearance of defeat, or the war could “break out of the boundaries that have currently kept it contained.”4 More often than not, outright victories and defeats are difficult to ascertain in such conflicts. Nations are forced to tailor their political-military objectives along more and more limited lines as the conflict stretches on. In fact, the success of military campaigns is claimed more frequently in the individual narratives articulated by each side rather than on the ground. Indian-Pakistani military engagements since 1998 illustrate these facts.

The challenge remains that when two nuclear-armed states engage in conflict, they have the capacity to hold the world hostage to nuclear destruction. Executing conventional wars in the shadow of nuclear arsenals may be possible, but it is not devoid of high risks.

Norm-Affirming Opportunities

Incidences of direct military engagement between nuclear-armed adversaries and the manner in which they have been conducted also illuminate another interesting issue pertaining to the perceived military utility of nuclear weapons. Nuclear strategists and practitioners understand well that nuclear deterrence is a game of psychological manipulation. Nuclear bluster and brinkmanship are an important dimension of nuclear deterrence, especially by weaker conventional powers. Like Pakistan or North Korea, Russia appears to have used nuclear saber-rattling to deter its adversary from the large-scale use of conventional forces. Despite all the noise that must accompany strategies of first use of nuclear weapons or those premised on the notion of “escalate to deescalate,” it is never easy to find the appropriate military use for nuclear weapons. The nature of the armament as a weapon of mass destruction and the attendant risk of retaliation after first use make it a blunt instrument, at least from the point of view of war-fighting.

Therefore, in all crises between nuclear-armed states, nuclear weapons have not shown themselves to be useful for achieving any worthwhile political or military objectives through premeditated first use. This is particularly the case when both sides have assured second-strike capabilities, thereby raising the risk of an exchange that would cause unacceptable damage to both sides.

Once this logic is understood, it is possible to envision some opportunities that can be exploited to strengthen the norm of nonuse of nuclear weapons and reinforce the basics of nuclear deterrence. What needs to be underscored is the fact that nuclear weapons are distinct from conventional weapons. The instantaneous release of large amounts of energy in the form of blast and thermal heat, ionizing radiation, and the long-term radioactivity from nuclear fallout are unavoidable with nuclear detonations.5 The empirical data from the destruction wrought on Hiroshima and Nagasaki by, respectively, 15-kiloton and 20-kiloton nuclear warheads are widely available. Today’s warheads are even more powerful and destructive. Although lower yields have been experimented with as one way of reducing the deleterious effects of nuclear explosions, a 2001 report concluded that even a ground burst of a nuclear yield as small as 1 percent of the Hiroshima weapon would “simply blow out a massive crater of radioactive dirt, which rains down on the local region with especially intense and deadly fallout.”6

Given that this is the true nature of the weapon, there hardly can be any credible scenarios where it could be used effectively to achieve an objective. Could any war aim be worth this cost to the adversary and to one’s own self given the retaliation that would likely follow? Over time, Washington and Moscow accumulated large stockpiles of varying yields in the hope of gaining an advantage in nuclear exchanges. Yet, neither country has been seriously inclined to test this hypothesis in real-life situations.

No matter how the war in Ukraine evolves, the nuclear threats by Russian President Vladimir Putin (R), shown with Defense Minister Sergey Shoigu, have revived fears of nuclear conflict and changed how countries think about deterrence and other nuclear-related theories. The two men attended the Victory Day Parade, marking the Soviet Union's defeat of Nazi Germany in World War II, in Red Square on May 9.  (Photo by Contributor/Getty Images)Nations cannot defend themselves by using nuclear weapons. They can only do so by deterring the adversary’s use of a nuclear weapon by the threat of retaliation. In fact, the threat of using these weapons in any scenario other than retaliation, such as against terrorists, conventional offensives, and cyberattacks or space attacks, could only be counterproductive by escalating hostilities. Clearly, these weapons are most effective for only a narrow role.

Embracing this simple reality could make it possible for nations to agree to accept no first use of nuclear weapons as a doctrinal precept. If deterrence is the only function that nuclear weapons can credibly perform, then a no-first-use doctrine does not put nuclear-armed states at a disadvantage. Rather, it brings many benefits. For one, it allows countries to retain their nuclear weapons for the sense of notional security derived from their presence until such time as nuclear-armed states begin to see them as useless. At the same time, the no-first-use policy liberates nations from the need to build and maintain large arsenals with first-strike capabilities, which bring their own risks of safety and security.

Moreover, the policy releases national leaders from having to make the momentous decision to breach the nuclear taboo, which can never be easy because the act will provoke retaliation. It also frees adversaries from the use-it-or-lose-it dilemma, which could trigger nuclear preemption. Thus, a no-first-use policy offers crisis and arms race stability even in the presence of nuclear weapons.7 Because nuclear weapons possessors are unwilling to relinquish their arsenals until conditions are “right,” a no-first-use policy can help create those conditions by constricting possibilities for using the weapon, thus making them useless over time.

Backing Off the Nuclear Precipice

Six decades after the Cuban missile crisis, the Russian-Ukrainian war has brought nations yet again to the nuclear precipice. Talk of World War III is in the air. Of course, the United States and NATO have taken adequate precautions to avoid any move that could propel the world toward nuclear escalation. Some Russian ministers have announced that their country has no reason to use nuclear weapons except to defend against an existential threat. These efforts contribute toward minimizing the chance of intentional nuclear use. Nevertheless, the inadvertent use of the weapons due to miscalculation, misperception, or accident should not be overlooked. Given that tensions are high and information warfare well in progress, one cannot dismiss the presence of a thick fog of war that could make countries stumble into nuclear use.

As a result, it is imperative that this moment be seized by all those who believe that living with nuclear weapons is too risky to drive home the dangers of nuclear weapons and the alarming challenges that they pose for states with nuclear weapons and those without. The very existence of these armaments adds to the risk of escalation to the nuclear level in every war. Additionally, these weapons trigger anxieties about nuclear blackmail and coercion among nonpossessor states.

The war raging in Ukraine offers an important opportunity to sensitize nations and their populations to nuclear risks. All could do with a stiff dose of nuclear learning. The fate of future generations will rest on the world’s behavior today.



1. Richard Falk and David Krieger, The Path to Zero: Dialogues on Nuclear Dangers (Boulder, CO: Paradigm Publishers, 2012), p. 26.

2. Raksha Mantri, “The Challenges of Limited War: Parameters and Options” (address, New Delhi, January 5, 2000),

3. See Nuclear Crisis Group, “South Asia: Post Crisis Brief,” June 2019,

4. Lawrence Freedman, “Escalators and Quagmires,” Comment Is Freed, April 29, 2022,

5. Some of these arguments draw on an earlier paper by the author. See Manpreet Sethi, “Back to Basics: Pledging Nuclear Restraints,” in Off Ramps From Confrontation in Southern Asia, ed. Michael Krepon, Travel Wheeler, and Liv Dowling (Washington: Stimson Center, 2017).

6. Robert W. Nelson, “Low-Yield Earth-Penetrating Nuclear Weapons,” Federation of American Scientists, n.d.,

7. With their declared no-first-use doctrines, China and India have demonstrated the benefits of this despite their long military stand-off since April 2020. See Ramesh Thakur and Manpreet Sethi, “India-China Border Dispute: The Curious Incident of a Nuclear Dog That Didn’t Bark,” Bulletin of the Atomic Scientists, September 7, 2020,

Manpreet Sethi is a distinguished fellow at the Centre for Air Power Studies in New Delhi.