The writer is research director at the European Council on Foreign Relations and a former official in the US state department
President Vladimir Putin announced on Sunday that he was putting Russian nuclear forces on “high alert”. Alert status probably means little in terms of increasing the risk of escalation in Ukraine. But Putin’s ominous declaration reminded the world that Russia has, among the many destructive tools in its arsenal, many thousands of nuclear weapons.
For most people in the west, the very idea of using nuclear weapons is simply unthinkable – and so they do not think about it. The cold war, in this view, proved that nuclear weapons are unusable.
But for better or for worse, we now live in a different world. The war in Ukraine, as well as the evolution in Russia’s thinking and its precarious military position, mean that nuclear escalation is a greater possibility than it has been since the early 1980s. It remains unlikely, but we need once again to think about it and consider how to further reduce the chances of it happening.
How could Russia’s invasion of Ukraine lead to a nuclear confrontation? The most likely route is through Russian employment of a tactical nuclear weapon. Tactical nuclear weapons are relatively smaller bombs intended to be used in battlefield situations against concentrations of enemy forces. Estimates vary widely but Russia probably has between 1,000 and 2,000 such weapons in its arsenal, with a wide variety of yields and delivery mechanisms. They also vary greatly in explosive effect but could destroy anything from an armored column to an entire town.
In the past decade, western analysts have worried that Russian military doctrine has become more dependent on nuclear weapons. Former Nato commander General Philip Breedlove often described a scenario where the Russians might attack one of the Baltic states, drop a tactical nuclear weapon on a Nato force concentration trying to counterattack and then negotiate a stand-down that secures their gains.
The current situation is obviously different, but it highlights that tactical nuclear weapons are probably not a weapon that would be used against the Ukrainians. It is not necessary to pay the price of crossing the nuclear threshold to achieve Russian goals in Ukraine. High-yield conventional weapons or the dreaded thermobaric bombs, which draw in oxygen to create an intense explosion, are more than sufficient for any effect they might want and do not force them to bear the nuclear stigma.
Nato presents an altogether different kind of problem for Russia. Nikolai Patrushev, a close adviser to Putin, said in 2009 that Russia might launch a pre-emptive nuclear strike “to repel an aggression with the use of conventional weapons not only in a large-scale but also in a regional and even local war” . Patrushev was essentially outlining a scenario in which a superior conventional force such as NATO attacked Russia. Patrushev’s view did not in the end inform Russia nuclear doctrine. But his message remains and highlights that tactical nuclear weapons are intended to send the following message to NATO leaders: “You may have a more impressive military than I do, but I care a lot more and will kill us all if necessary.”
Now, the Russian military is heavily engaged in Ukraine and thus particularly vulnerable to a NATO conventional attack in Belarus and western Russia, as well as in Ukraine. So in the current scenario, Russian leaders are most likely to use a tactical nuclear weapon to prevent or put an end to NATO intervention. In theory, therefore, it should be straightforward to avoid that outcome by not intervening. The west, in the minds of its own leaders, has no intention of intervening so they may not feel there is much chance of nuclear escalation.
The problem is that, given the paranoia of Russian leaders, they probably expect NATO intervention, and may even believe it is already happening given European and American arms deliveries and NATO troop movements to eastern Europe. They may view NATO troop concentrations in states on Ukraine’s eastern flank as potential intervention forces and they may lack sufficient precision-guided weapons in their already very depleted inventory to attack them conventionally. They might also view weapons depots in neighboring states that are supplying Ukrainian government forces as legitimate targets.
Russian attacks of these sorts are not likely, but they are possible. Beyond the horrible death and radioactive fallout they would cause, such attacks would cross the nuclear threshold for the first time since 1945 and thus open the path to further nuclear escalation to the strategic level (ie the end of the world). Given that we very much want to avoid that, western leaders might think about taking steps to make it even less likely.
Such steps would involve thinking carefully about how the Russians understand “intervention”. Russian leaders, for example, might see volunteers from NATO countries filtering into Ukraine as covert advance guards for a full-scale intervention. They might regard arms convoys coming to Ukraine from NATO states as the functional equivalent of intervention. And, depending on their orientation, they might see troop dispositions in eastern flank states or troop movements to, say, help manage refugee flows at the border as a precursor to intervention.
If it is truly not the intention of western leaders to intervene, they should make sure that their forces act in ways that will convince Russian leaders of that. The world may depend on it.