What would the world look like after Russia used nuclear weapons in Ukraine?  Much depends on context, but we can still imagine what happens on the Day After.

What Will the Battlefield in Ukraine look like?

The impact of the use of a nuclear device in Ukraine will depend on the details. 

Like any large-scale industrial army, the Ukrainian Armed Forces have obvious pressure points that would be vulnerable to nuclear attack. These include logistical centers, command and communications nodes, and concentrations of front-line forces.

During the Cold War the Soviet Union expected to use tactical nuclear weapons against NATO (and expected that NATO would use them in return) and it is therefore likely that the Russian armed forces have workable theories as to how they might best use tactical nukes to inflict damage on Ukraine’s fielded forces. At the same time, we should refrain from overstating the damage that such weapons can inflict on forces in the field, as most tactical nukes have limited destructive effects and rely on careful targeting.

Of the political effect on the war we can say almost nothing of use at this point. We don’t know whether the Ukrainian leadership and polity would become more or less flexible following a nuclear detonation.  The only example of such an attack comes from Japan, and the differences in context are vast.

We can imagine good arguments either way about Ukrainian reaction, but we don’t know until a bomb actually explodes.

At the same time, it’s difficult to predict the impact within Russia. There does seem to be some appetite for escalation in certain segments of Russian public opinion, but the use of a nuclear weapon on Ukraine would undoubtedly provide a shock to the Russian political system. We don’t know enough to judge the impact of that shock.

The Nuclear World

Three of the world’s nuclear powers (France, the UK, and the US) stand firmly against Russia in this conflict. The rest (North Korea, China, Pakistan, India, and Israel) have taken more ambiguous positions. 

Russian use of a nuclear weapon in Ukraine could shake both of these groups. In the former bloc, many have argued that Russian first use should be met with immediate escalation, such as attacks against Russian naval assets or fielded Russian forces in Ukraine.  Strategic nuclear arsenals would presumably secure these states against Russian retaliation, although the dangers of such a move are obvious.

The attitude of the rest of the nuclear powers is more complex. While all of the nuclear powers have reserved some attention to nuclear warfighting rather than to deterrence, the primary job of their arsenals has involved deterrence. 

If we’ve decided now that we fight wars with nuclear weapons rather than simply hope that they never go off, then the military establishments across the nuclear world will need to reconfigure their approaches. 

Serious multilateral diplomacy might be able to put the genie at least partially back in the bottle, but maybe not; efforts to curtail the expansion of existing arsenals would probably become a lost cause.

In more immediate terms, Russia’s use of a nuke would likely have profound implications for Bloc Ambiguous, with unpredictable effects on popular and diplomatic opinion.  India and China at least would likely issue condemnations of the Russian attacks, although the impact of these condemnations would depend on context and caveats.

Either China or India could inflict severe damage on the Russian war effort and the Russian economy by joining the sanctions regime, but it is not at all clear that a nuclear attack would trigger such a move.

The Non-Nuclear World

The war in Ukraine has already transformed the non-proliferation environment. 

In the 1990s Ukraine gave up the nuclear weapons it had inherited at the collapse of the Soviet Union in return for ambiguous assurances of security from Russia and the United States.  Whether Ukraine could have made any use of those weapons is a separate question from the impact of the dissolution of this arrangement on international opinion. 

Put simply, it seems quite reasonable to suggest that countries that are considering nuclear programs will view Russia’s invasion of Ukraine as a green light; guarantees and declarations cannot ensure security, but nuclear weapons can.

If Russia uses nuclear weapons directly against Ukraine, we can expect to see this interpretation go into overdrive.

Nuclear weapons will then become a means through which nuclear states directly discipline non-nuclear states, presumably with no observable political implications. 

In addition to pursuing strategic nuclear systems, we can expect non-nuclear states to look at the prospects of developing tactical nuclear weapons with battlefield applications. 

Showing the world that nuclear weapons don’t simply ensure security but also make it easier to win wars will only make them more attractive to countries across international society.

A Changed World? 

Non-proliferation has been the guiding principle that has united the world’s wealthiest and most powerful countries since the early 1990s. It animated efforts to limit and transfer control of the old Soviet nuclear arsenal. It animated diplomacy towards Iraq, Iran, and North Korea over the past two decades, with mixed results.

Even if the basic consensus across existing nuclear powers holds that new entrants are bad (and there’s no guarantee that such a consensus can survive this conflict), the nuclear powers already have their work cut out in order to curtail proliferation in the Middle East, the Indo-Pacific, and elsewhere.

If Russia uses a nuclear weapon for battlefield effect, then all bets are off; Moscow may determine whether proliferation is in its broader interest (if only for the disruptive effect on global politics), or not, but leaders around the world will begin to see nuclear weapons as something useful, rather than as a totem of deterrence.

That’s very bad news both for efforts to reduce existing arsenals and for the project of limiting the proliferation of new nuclear-capable states.

About the Author: Dr. Robert Farley  

Dr. Robert Farley has taught security and diplomacy courses at the Patterson School since 2005. He received his BS from the University of Oregon in 1997, and his Ph.D. from the University of Washington in 2004. Dr. Farley is the author of Grounded: The Case for Abolishing the United States Air Force (University Press of Kentucky, 2014), the Battleship Book (Wildside, 2016), and Patents for Power: Intellectual Property Law and the Diffusion of Military Technology (University of Chicago, 2020). He has contributed extensively to a number of journals and magazines, including the National Interest, the Diplomat: APAC, World Politics Review, and the American Prospect. Dr. Farley is also a founder and senior editor of Lawyers, Guns and Money.