The Real Russian Nuclear Threat

To hear U.S. officials tell it, there is little risk that the war in Ukraine will lead to nuclear escalation. “We don’t have any indication that Mr. Putin has any intention to use weapons of mass destruction—let alone nuclear weapons,” said White House spokesperson John Kirby in January. At a Senate hearing in early May, Director of National Intelligence Avril Haines stated that Russia was “very unlikely” to use its nuclear arsenal. Yes, CIA Director William Burns said a February speech, the United States must take Putin’s nuclear saber rattling seriously. But the purpose of such rhetoric, Burns continued, was “to intimidate us, as well as our European allies and Ukraine.” It was not to signal that Russia was actually thinking about using its weapons.

Washington’s incredulity is to some extent understandable. The advent of the war triggered fears of outright nuclear conflict between the West and Russia. That period of somewhat frenzied speculation has passed. The war has since settled into a grinding—but conventional—stalemate. To be sure, U.S. officials are still concerned that Russia may use tactical nuclear weapons on the battlefield. “I worry about Putin using tactical nuclear weapons,” U.S. President Joe Biden said in June. The risk, he continued, is “real.” But officials do not appear to believe that the war in Ukraine could lead Russia to use its nuclear arsenal against a NATO state, however furious it is at the West for supporting Ukraine.

That is a mistake. U.S. officials have it backward. It is actually quite unlikely that Russian President Vladimir Putin will use a nuclear weapon on the battlefield in Ukraine, but it is very possible that he will move toward using one against NATO. Unlike the West, Putin may not fear a nuclear standoff: he is well versed in Russia’s nuclear arsenal and the tenets of nuclear deterrence, and possibly sees himself as uniquely suited to navigating a nuclear crisis. And Putin has been remarkably consistent that Russia is willing to use nuclear weapons against NATO to defend its interests in Ukraine. Even eight years ago, in a television interview done a year after Russia invaded Crimea, Putin declared that he had been ready to place Russian nuclear forces on alert to prevent Western forces from interfering in Moscow’s takeover of the peninsula.

Russian nuclear weapons use is not imminent. But if Putin does escalate the war, for instance by attacking NATO with conventional weapons, he will likely move very swiftly, so as not to give the United States a chance to maneuver away from a crisis. Washington will struggle to deter a Kremlin so emboldened. Ukraine is too central to the Kremlin’s ambitions—and too secondary to the United States’—for Putin to believe any American threats. Ultimately, Putin will expect the United States to back down before fighting a nuclear conflict over land so far from home.

To avoid the worst, the United States needs to find new ways to prevent Russia from using its arsenal. It must persuade the country’s officials, including ones along the military command chain, to subvert and obstruct decisions that might lead to a nuclear attack. It needs to convince Russian elites that their country can concede on Ukraine without suffering a catastrophic defeat. It must rally other countries, especially neutral ones, to delegitimize nuclear use and convince Putin that he will be making a dreadful mistake if he turns to his nuclear arsenal. And it must do so now. That way, Washington can avoid having to make dangerous decisions later, under the intense pressure of a nuclear standoff.

LOCKED AND LOADED

Russia has not been bashful about its nuclear arsenal. From the moment the country launched its invasion, Moscow has tried to intimidate the world by gesturing at its weapons. Shortly before attacking Ukraine, Russia carried out an unusually timed exercise of its nuclear launch systems. A year later, in February 2023, it suspended participation in the New START treaty, which regulated how many nuclear weapons Moscow and Washington could have. In March, the Kremlin announced that it would move some of its nuclear weapons into Belarus. In October, Putin suggested that Russia might restart nuclear testing. All the while, Russian government officials have threatened to launch a nuclear attack, as former President Dmitriy Medvedev did in July, when he said Russia could “use nuclear weapons” to conclude the war in a few days.

U.S. officials, of course, have paid attention to these threats, but they have not been convinced by them. They imagine that Moscow may use small so-called tactical nuclear weapons on the battlefield, but not large so-called strategic ones against NATO states. According to Politico, National Security Adviser Jake Sullivan told U.S. experts in February that there was little fear that Russia would use strategic nuclear weapons in Ukraine or against the West, but some remained concerned that Russia could use tactical weapons. Putin, their thinking goes, might use these weapons to help Russian forces halt a Ukrainian attack that appeared on the verge of taking back Crimea or inflicting a significant defeat that threatened to push Russian forces out of eastern Ukraine.  

But the growing complacency among U.S. officials is based on a misunderstanding of Putin’s rhetoric and the dynamics that keep Moscow from using nuclear weapons. When Putin invokes his arsenal, he is not trying to warn that Russia could use tactical nuclear weapons in Ukraine. Rather, his rhetoric is designed to threaten NATO itself. It is a blinking red light, a warning to American decision-makers that Moscow is willing to create a nuclear confrontation with Washington if needed to win in Ukraine.

So long as Putin remains optimistic about Russia’s odds, he is unlikely to rock the boat in Ukraine.

To see why, consider, first, the state of the battlefield. Tactical nuclear weapons would do little to help Russia break the stalemate. Ukrainian forces are well entrenched along a frontline that extends for roughly 600 miles, and so even dozens of tactical weapons would not be enough to let Russia push through. Even if they were, Russia does not have the maneuverable reserve forces needed to exploit any opening created by these weapons. A nuclear attack would, of course, be a terrifying event for Ukrainians to witness, but it would still not break the will of the Ukrainian people or compel Kyiv to surrender. Ukrainians have fought with tremendous courage through all kinds of atrocities, and a tactical nuclear attack would only be another entry in the register of Russian brutality. Ukrainians have said as much when responding to polls. According to surveys by the Munich Security Conference and Ukrainian think tanks, the country’s public is unwilling to surrender to Moscow and stop fighting even in the face of nuclear threats.

If anything, tactical nuclear strikes would hurt Russia’s war effort. Such attacks would likely strengthen the West’s desire to help Ukraine, just as it was starting to ebb. (Western politicians of all stripes have a strong incentive to ensure that nuclear weapons are never used in war.) A nuclear strike might also prompt China and India—the Kremlin’s two most important international partners—to abandon Russia. Both Beijing and New Delhi have already made public statements designed to dissuade Moscow from using nuclear weapons. They would not be happy if Putin ignored them.

For Putin, there is little to gain from using nuclear weapons in Ukraine, and much to lose. In fact, right now he believes that there is little to gain from using nuclear weapons anywhere. Putin thinks that Russia can win in Ukraine by conventional means. “Almost along the entire frontline, our armed forces, let’s put it modestly, are improving their position,” he said in a December 14 press conference. He also noted that Western support for Kyiv appears to be in decline, declaring that soon, the “freebies” afforded to Ukraine would “run out.” So long as Putin remains optimistic about Russia’s odds, he is unlikely to rock the boat by engaging in escalation.

But Putin may not always feel this way. If the West makes a strong, renewed commitment to support Kyiv as it tries to retake all occupied territory and provides Ukraine with long-term financing support and a bolstered defense industry, Putin might decide that he may not be able to grind Ukraine down through attritional warfare. If, in addition, Western economic sanctions finally start to significantly disrupt the Russian economy, Putin may conclude that time is not on his side. Russia’s president might decide to double down instead of waiting Ukraine out. The real escalation risks would then start.

ZERO TO SIXTY

For the United States and its allies, the first set of escalatory risks might seem like more bluster. The Kremlin, for example, could begin by moving its big, long-range nuclear weapons carriers into deployed and dispersed positions, beyond their normal bases, which are vulnerable to U.S. attacks. It could, for example, send the bulk of its ballistic missile submarines out to sea, move large numbers of its strategic missile forces into the vast Russian forests, and load nuclear weapons onto strategic bombers. Such actions fall well short of actually using nuclear bombs, but they would still be deeply alarming. They would undoubtedly catch Washington’s attention, dramatically heighten tensions, and immediately force Western leaders to account for the risk of nuclear war in their calculus.

From there, Moscow might actually begin using force against NATO. It could down a NATO aircraft over an allied country or international airspace. It could attack a NATO ship in the Black Sea. Or it could attack what it claimed were arms convoys bound for Ukraine while they were moving through a country in NATO’s eastern flank. Such steps would quickly expand the scope of the conflict, bringing NATO into the fight. Moscow might augment this step by detonating a nuclear weapon in the open ocean, in what is called a demonstration strike.

Finally, in a worst-case scenario—one where the Kremlin sought to shock the world into ending the war in Ukraine quickly and on Putin’s terms—Russia could actually launch a nuclear weapon directly at NATO territory. Although Putin seemed to pour cold water on the idea at an annual forum in October, saying that Russia did not need to lower the threshold for nuclear use, it might look necessary if the war were clearly trending against Russia. Eighty percent of military aid to Ukraine flows through one airbase in eastern Poland, and so that base would probably be a prime target. The United States might then retaliate with a nuclear strike of its own, bringing the world to the edge of destruction.

It may not take long, from the time he begins escalating, for Putin to move from sharp nuclear signaling and conventional attack to ordering a nuclear strike. If Putin were to escalate slowly, launching smaller attacks and seeing how NATO reacts, he would risk inciting a conventional conflict—probably with NATO forces intervening directly into Ukraine and possibly within Russia itself—in which the West has a clear advantage. NATO’s conventional forces are superior to Russia’s, and so Putin will not want to give Washington time and space to react, allowing it to bring its capabilities to bear. He will therefore want to reach the nuclear level—where Russia is a peer of the United States—as quickly as possible.

Washington cannot deter Putin from escalating.

U.S. officials, of course, do not want Moscow to resort to nuclear weapons, even though they seem unconvinced that he will. As a result, they have attempted to scare Russia away from escalating by threatening “catastrophic consequences,” as the White House put it in September 2022, should Putin use his arsenal. But such warnings are unlikely to deter Russia’s president. Putin will see this threat as a bluff; he knows that, ultimately, Washington does not want to risk a nuclear conflict over Ukraine. He is also profoundly committed to winning in Ukraine, to the point where he might decide to rapidly escalate even if he thought the United States was serious about responding with force. He would probably doubt the severity of any U.S. threat and calculate that, in the end, Washington would choose to compromise rather than launch nuclear strikes against Russia itself, which could entail a nuclear response against the U.S. homeland.

The unfortunate truth is that Washington cannot deter Putin from escalating to the point where he uses nuclear weapons because of the war in Ukraine. Although he would not take such escalation lightly or dismiss the serious risks for Russia, Putin would anticipate that he could win the war of wills in a nuclear crisis. If it wants to avoid a nuclear standoff, Washington must therefore take a different tack. U.S. policymakers should instead pursue policies aimed at subverting Russia’s decision-making, so that if Putin orders escalatory steps he faces internal pushback. That means they need to try empowering Russian officials who want to obstruct any effort by Putin to go nuclear. Doing so will not be easy, given that U.S.-Russian relations are about as poor as can be. But Washington can start by engaging more with Moscow, odious as that may seem. The only way for U.S. officials, including in the intelligence community, to cultivate dissent among Russian officials is to forge more direct contacts.

The United States must also persuade Russian officials that there are paths out of Ukraine that do not end in either victory or a humiliating defeat. Washington could, for example, suggest that only the most senior officials could be punished for starting the war, that any reparations to Ukraine would be limited, and that there is a path for lifting sanctions against Russia and allowing the state to reenter the community of nations. But exactly what such an outcome would entail need not be spelled out explicitly. Top Russian officials simply have to know that their choice is not between capitulation and nuclear escalation.

Still, the United States cannot bank on Russian officials to stop Putin from using nuclear weapons. They must simultaneously rally neutral states to pressure Moscow away from escalation. They need to push these states to be clear in their conversations with Russian officials that any nuclear use is illegitimate, and that it would lead to them severing all direct and tacit support for Russia’s war effort. China’s and India’s public warnings about nuclear strikes were both positive signs, but they and other countries—such as Turkey, the United Arab Emirates, and Saudi Arabia, all of which are helping keep the Russian economy afloat—can do more.

And they must. Nuclear brinkmanship is a dangerous game, particularly with an authoritarian leader such as Putin. This is no time for complacency. For the world to head off nuclear war, countries will have to persuade Moscow that victory in Ukraine is simply not worth the costs of bringing the world to the precipice—or over it.