We’re not out of the woods yet. The Russian invasion of Ukraine has been the most dangerous situation in terms of nuclear war risk since at least 1983 (Able Archer, KAL-007) and maybe even since the Cuban missile crisis. The risk of nuclear escalation may seem less acute at this point in the war, with the battlefield stuck in a relatively stable war of attrition and the US pursuing peace talks. However, dangerous pitfalls lurk ahead. The international community must take care to not get caught in them and instead steer this conflict to a safe resolution.
Based on my own experience studying the history of incidents that threatened to escalate to nuclear war, two scenarios stand out to me. One is rooted in military advances by Russia, the other in military advances by Ukraine. While neither is inevitable, both are plausible given the current state of affairs on the battlefield, the underlying motivations of the various combatants, and the dynamics of nuclear escalation. Given the extreme stakes of nuclear war, these scenarios merit attention even if they may be unlikely, as is generally appropriate for low-probability, high-severity risks.
Scenario 1: Miscalculation on NATO Turf
In this scenario, Russia escalates hostilities with one or more NATO countries. One or both sides miscalculate, causing the conflict to further escalate to nuclear war.
Throughout the war in Ukraine, and indeed even before it, Russia has maintained that it is at war with the West, with Ukraine being an instrument of Western aggression. This can be traced to post-Cold War issues such as NATO expansion. Russia may now be pursuing a new international order in which it plays a leading role, or even the leading role.
Thus far in the war, Russia has abstained from directly attacking NATO territory, apparently due to concerns about escalation. That is indeed helpful behavior. However, Russia has meanwhile engaged in indirect hybrid warfare attacks of subversion and sabotage against NATO countries. Russia may, at a later time, after it has rebuilt its military, decide to wage direct war against one or more NATO countries. That may be especially likely if it believes that the NATO alliance has weakened and would not join in retaliation. Recent US behavior has raised doubts about its commitment to NATO; if this persists, it could tempt Russia to attack.
Russia presumably (hopefully?) would not attack a NATO country if it knew for certain in advance that it would lead to large-scale nuclear war—that would be suicide. However, it could get this wrong. It could miscalculate in its expectation that NATO would not retaliate, similar to its catastrophic miscalculation that Ukraine would not put up fierce resistance to its invasion in 2022. The result would be a direct shooting war between NATO and Russia, possessors of the two largest nuclear arsenals in the world. That is the worst-case situation for potential nuclear escalation.
Nuclear escalation could occur in several ways. Once hostilities have commenced, there would be potential for inadvertent escalation, in which the interplay between non-nuclear forces pushes the conflict to nuclear war despite neither side desiring this. An active shooting war would also bring heightened risk of false alarms that prompt one side to mistakenly believe it is under nuclear attack and launch nuclear weapons in response. It is also possible that one side would intentionally choose to initiate nuclear war, especially to avoid battlefield defeat.
Scenario 2: A Gamble in Ukraine
In this scenario, Russia is facing military defeat in Ukraine. To avoid this fate, it launches a nuclear attack.
Currently, the war is a grinding, slow-moving war of attrition, but Russia has a slight edge on the battlefield and has been gradually gaining territory. Russia has a clear advantage in the number of people it can deploy, but it nonetheless faces major challenges. Its military stockpiles and financial resources are being depleted at an unsustainable rate; according to one projection, Russia will lose the ability to maintain its current activities in 2026 or 2027. Some analysts believe that Ukraine can win the war of attrition.
If Russia finds itself losing the war, it could simply accept defeat, or it could escalate. One option for escalation would be to attack Ukraine’s military supply chains on NATO territory. That would reduce Ukraine’s warfighting ability, but it would risk escalating the war with NATO, as in Scenario 1.
An alternative would be for Russia to use its nuclear arsenal to try to turn back Ukraine. It could start with a test detonation in a remote location to demonstrate resolve. If that doesn’t work, it could bomb strategic sites in Ukraine, up to and including Kyiv. Russia has enough nuclear weapons to more-or-less obliterate Ukraine, and there isn’t really anything Ukraine or anyone else can do to prevent it. However, NATO could respond, and respond it might; previously, Biden said that any Russian nuclear attack “would entail severe consequences”. Exactly what would happen next cannot be known in advance, but a full-scale NATO-Russia nuclear war is one possibility.
Given the risk that a nuclear war would pose to Russian territory, one might think that Russia would not want to initiate nuclear war. Unfortunately, there are reasons to believe that it would anyway, despite the risk. Russian nuclear doctrine has long permitted the use of nuclear weapons in response to a non-nuclear attack on Russian territory; that could include territory claimed by both Russia and Ukraine. Recently, the doctrine was revised to be more permissive, covering attacks on Russia that Ukraine is already executing.
Another concern comes from Russian domestic politics. Putin currently boasts an 88% approval rating and an overall secure hold on power. However, if the war effort is failing, that could weaken Putin’s domestic standing. After all, starting the war was Putin’s decision, and it has cost Russia dearly. If all of that suffering ends up bringing nothing for Russia, that puts Putin in a difficult position. Some of the political fallout could be mitigated by Russia’s mighty domestic propaganda machine, but a crushing defeat in Ukraine may be too much for the media to spin. Putin is said to have a strong desire to remain in power for the remainder of his life. He may find that rolling the dice on a nuclear attack is his best option, even if it is not Russia’s.
This scenario was discussed extensively earlier in the war. I have not found any more recent discussions. For now, with Russia advancing on the battlefield, the scenario does not appear imminent. However, depending on how Russian forces are depleted, this is one to keep an eye on.
How to Manage the Risk
Throughout the war, many commentators have dismissed the risk of nuclear war, arguing that Russia’s nuclear threats are mere bluffs, and that the West should ignore them and instead aggressively support Ukraine. That is a mistake. Russia’s threats might be bluffs, but there is no way to know for sure in advance. Furthermore, accidents and miscalculations could bring about escalations that neither side wants. As worthy as it may be to support Ukraine, we ignore the risk of nuclear war at our own peril.
Accounting for nuclear war risk does not mean yielding to every nuclear threat and letting Russia have whatever it wants. Nuclear war risk is an important factor, but it isn’t the only one. Furthermore, yielding to Russia in Ukraine could even increase nuclear war risk by emboldening it to push past Ukraine into more dangerous territory. A better approach is to provide Ukraine with cautious, gradually increasing support—exactly what NATO has already been doing. Critics have argued that this leaves Ukraine shorthanded, but it provides a reasonable balance between supporting Ukraine and avoiding dangerous escalation.
To reduce the risk of Scenario 1, NATO should be very clear about its resolve to stand up to Russian aggression. The US in particular should be clear about its commitment to NATO. This would reduce the chance of Russian miscalculation. Both sides should also have careful warfighting procedures to reduce the risk of inadvertent escalation. If neither side wants nuclear war, they may even be able to cooperate to avoid it.
Scenario 2 is more challenging. In principle, the risk can be reduced by allowing Russia to maintain sufficient wins on the battlefield. In practice, Ukraine would not consent to that, nor should they be expected to. Instead, the hope would be to get Russia to accept defeat without resorting to nuclear attacks. It may help if Russia loses slowly instead of in a dramatic collapse. As with NATO’s gradually increasing support for Ukraine, a slow defeat could give Russia time to adjust and avoid moments of panic. However, once again it is difficult and arguably inappropriate to expect Ukraine to proceed cautiously on the battlefield if and when it has opportunities for major breakthrough.
A more reliable and defensible approach for Scenario 2 would be to appeal to the international community to put pressure on Russia. China and India have already warned Russia not to use nuclear weapons in Ukraine; more of this might reduce any temptation Russia may have for nuclear escalation. This wouldn’t solve the underlying problem of Russia’s military predicament, but it could at least reduce the risk.
Finally, to the extent that it can be done, all parties should seek to “responsibly” manage nuclear war, should one break out. The idea of a responsible nuclear war may seem absurd, and it is easy to argue that any nuclear war would be deeply irresponsible. However, not all nuclear wars are equal. As painful as it may be to consider, the impacts of nuclear war are much less bad for a small nuclear war than a large one. The US and Russia both possess thousands of nuclear warheads. A war that uses a substantial portion of these is far worse than a war that only uses one or two. We already know that humanity as a whole can survive a war with one or two nuclear explosions—this happened in Hiroshima and Nagasaki. Prospects for surviving a larger nuclear war are more tenuous, for reasons including global effects such as nuclear winter. So, as ridiculous as it might seem to consider, it is important to plan to manage any nuclear war in a way that would reduce its overall severity.
Ultimately, there needs to be an improved relationship between Russia and the West. In my opinion, that is the only reliable means of reducing the risk of NATO-Russia nuclear war down to zero, or at least down to some acceptable minimum. Given the horrific atrocities Russia has committed in Ukraine and its aggression toward the West, this may not happen any time soon, but it still is a worthy goal to work toward. Meanwhile, the more immediate nuclear war scenarios must be avoided.
Image credit: Ministry of Defence of the Russian Federation
