Russian President Vladimir Putin habitually rattles his nuclear sabres when things start looking grim for Moscow, and has done so long before his ill-advised invasion of Ukraine.

In February 2008, he promised to target Ukraine with nuclear weapons if the United States stationed missile defences there. In August the same year, he threatened a nuclear war if Poland hosted the same system. In 2014, Foreign Minister Sergei Lavrov warned that Russia would consider nuclear strikes if Ukraine tried to retake Crimea.

A year later, the Kremlin said it would target Danish warships with nuclear missiles if they participated in NATO defence systems. And within the space of a few months – in December 2018 and February 2019 – Putin warned the US that nuclear war was possible, and then promised to target the American mainland if it deployed nuclear weapons in Europe.

Since the invasion of Ukraine, the Kremlin has waggled its nuclear arsenal so many times it’s starting to become tedious. Even the most peripheral slight is apparently fair game, like former President Dmitry Medvedev’s invocation of nuclear retaliation if the International Criminal Court (ICC) pursued war crimes investigations against Russian soldiers.

Deterrence

One explanation for Russia’s behaviour is that it’s attempting to deter NATO from attacking it. For nuclear deterrence to be effective, states possessing such weapons require three things, commonly referred to as the “Three Cs”: capability, communication and credibility.

Russia certainly has the first of these. With nearly 6,000 nuclear warheads it’s the world’s most heavily armed nuclear state. It also communicates – loudly and with regularity – those capabilities.

But the question of credibility remains an open one, reliant on the perceptions of others. Put simply, the US and other nuclear states must believe Russia will use nuclear weapons under a certain set of conditions, usually in retaliation for a similar attack or when it faces a threat to its survival.

But will it really use them?

Russia’s declared nuclear doctrine identifies the circumstances under which it would employ nuclear weapons in a fairly rational and sensible manner.

Its 2020 Basic Principles on Nuclear Deterrence stresses that Russia will reserve the right to use nuclear weapons “in response to the use of nuclear and other types of weapons of mass destruction against it and/or its allies”. Or, if Russia comes under such severe conventional attack that “the very existence of the state is in jeopardy”.

Putin’s spokesman Dmitry Peskov addressed this directly on March 28, stating “any outcome of the operation [in Ukraine] of course isn’t a reason for usage of a nuclear weapon”.

Yet this has not prevented widespread acceptance of the view that Russia would use nuclear weapons in order to seize the advantage in escalation control. This idea, commonly referred to as “escalate to de-escalate” is even embedded in the US 2018 Nuclear Posture Review’s assessment of Russian intentions.

But the Kremlin’s perpetual nuclear signalling has much more to do with its attempts to intimidate and attain reflexive control over the West. In other words, it’s seeking to get the US and other NATO members to so fear the prospect of nuclear war that they will accede to Russian demands. That makes it a coercive strategy, but crucially one that relies on never actually being tested.

There are plenty of signs this is working. In April 2022, Germany’s Chancellor Olaf Scholz based his decision not to supply heavy weapons to Ukraine with the justification that “there must not be a nuclear war”.

A number of Western commentators have also begun reconsidering the “nuclear taboo”, worrying Putin might resort to nuclear weapons in Ukraine if he feels backed into a corner, or to turn the tide of the war. One particularly agitated opinion piece in the New York Times called for immediate talks before major power war became inevitable.

It makes little sense for Russia to go nuclear in Ukraine

But what if the Kremlin’s recent nuclear threats are aimed less at NATO and more at Kyiv? Under those conditions, the logic of nuclear deterrence (threatening a non-nuclear country) do not apply.

There are several reasons Putin might seek to use nuclear weapons against Ukraine: a decapitating strike, to destroy a large portion of Ukraine’s armed forces, to cripple Ukrainian infrastructure and communications, or as a warning.

This also generally means using different types of nuclear weapons. Rather than large city-busting bombs, Russia would employ smaller non-strategic nuclear warheads. It certainly has plenty of them: about 2,000 warheads in Russia’s stockpile are tactical nuclear weapons.

But none of these scenarios make sense for Russia. While Moscow has returned to regime change in Ukraine as a war aim, using a nuclear weapon to take out Volodymyr Zelenskyy would be difficult and risky. It presupposes ironclad intelligence about his location, entails significant loss of civilian life, and requires Moscow to accept significant destruction wherever Zelenskyy might be. It would hardly look good for victorious Russian forces to be unable to enter an irradiated Kyiv, for instance.

Punching nuclear holes in Ukrainian lines is equally risky. Ukraine’s army has deliberately decentralised so it can operate with maximum mobility (often referred to as “shoot and scoot”). Putin would have to order numerous nuclear attacks for such a tactic to be effective. And he would be unable to prevent radioactive fallout from potentially blowing over “liberated” portions of Donbas under Russian control, not to mention Western Russia itself.

Another possibility is a high-altitude detonation over a city, doing no damage but causing a massive electromagnetic pulse (EMP). An EMP attack would fry electrical systems and electronics, bringing critical infrastructure to a standstill. But again, it would be difficult to limit EMP burst effects to Ukraine alone, and it would leave Moscow with very little remaining usable industry.

Finally, the Kremlin might seek a demonstration effect by detonating a nuclear device away from populated areas, or even over the Black Sea. This would certainly attract attention, but would ultimately be of psychological value, without any practical battlefield utility. And Russia would join the US as the only countries to have used such weapons in anger.

Is Russia rational?

In all this, there’s naturally a big caveat: the assumption Russia’s regime is rational.

Having accrued vast personal fortunes and a taste for luxury, Russia’s rulers are likely in no hurry to commit suicide in a major nuclear cascade.

However, since there’s no way of being certain, the West must continue to take Russian nuclear posturing seriously – but also with healthy scepticism. Indeed, if the West capitulates to Russian demands due to fears of nuclear war, it will further embolden Putin and show other nations nuclear brinkmanship is appealing.

But Russia arguably faces the bigger risk here. If Putin uses nuclear weapons against Ukraine or a NATO member it would also make it very difficult for states that have quietly supported it (such as China) or sought to benefit from its pariah status through trade (like India) to continue to do so. It would also likely engender a broader war that he has tried hard to avoid.

Let’s continue to hope Moscow, although often misguided, remains rational.

Matthew Sussex, Fellow, Strategic and Defence Studies Centre, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.