Recent developments in Ukraine suggest Russian military commanders have exhausted their ability to effectively respond to a Ukrainian escalation in fighting, which is expected any day. An influx of 300,000 new soldiers over the winter has done little to improve the fighting of Russian units, and the reported appearance of 1950s Russian tanks near the battlefield confirms Russian materiel is running out. President Vladimir Putin's bombing campaigns have not broken Ukraine. It is becoming clear, in my view, that the only way he can meet escalation with escalation is by introducing nuclear weapons.

Moreover, during the past 12 months, Putin has laid the groundwork for using a tactical nuclear weapon in Ukraine. He has removed domestic and operational barriers to doing so and has created justifications, fabricated and real, so that his people support him. In speeches and interviews, he has made the case that Russia is under existential attack — a situation, under Russian policy, that warrants the use of nuclear weapons. He has reshuffled his military leadership accordingly, assigning the three generals responsible for employment of tactical nuclear weapons to command his “special military operation” in Ukraine. He already has tactical reasons to explode a nuclear weapon: saving Russian soldiers’ lives, shortening the war, destroying Ukrainian forces. He also has strategic reasons: rejuvenating the deterrent value of his nuclear arsenal and proving that he is not a bluffer.

Putin’s threats have included both strategic nuclear weapons, which can reach the United States, and tactical nuclear weapons, which are generally smaller in explosive power and could be launched from shorter distances to strike Ukraine. His threats include preemptive strikes against those who threaten the survival of Russia. Unlike Ukraine, the U.S. and NATO have their own nuclear weapons to deter a Russian strike. But they have made it clear they will not use their nuclear weapons to defend Ukraine. This leaves Ukraine especially vulnerable to nuclear attack.  

Many Western experts say they take the threat of a Russian nuclear strike in Ukraine seriously but make the mistake of asserting that the odds are low. The result is that many officials view the problem of tactical nuclear weapons as serious but not urgent. Earlier this month, U.S. Director of National Intelligence Avril Haines told a Senate hearing that Putin's weakened conventional force would make him more reliant on "asymmetric options," including nuclear capabilities, for deterrence, but that it was "very unlikely" that Moscow would use nuclear weapons in its war against Ukraine. Speaking at the same hearing, the director of the Defense Intelligence Agency, Lt. Gen. Scott Berrier, also assessed the chances as "unlikely." 

In fact, the evidence is strong that the problem is urgent and I argue that Putin will use a tactical nuclear weapon in his war in Ukraine. Western leaders need not wonder about Putin's nuclear-use red lines and how to avoid crossing them while supporting Ukraine, in my view. Putin is not waiting for a misstep by the West. He has been building the conditions for nuclear use in Ukraine since early in the war and is ready to use a nuclear weapon whenever he decides, most likely in response to his faltering military's inability to escalate as much as he wishes by conventional means. This article will not consider exhaustively what may prompt Putin's decision, but we should not fool ourselves by thinking we can prevent it. Instead, we should prepare responses for a new world in which the nuclear genie is out of the bottle.

Russia’s Increased Reliance on Nuclear Weapons

For much of the past 80 years, Russia’s security has rested on two pillars whose relative strength has waxed and waned — its conventional ground forces and its nuclear weapons. The conventional forces have been used to influence, bully and force Russia’s neighbors and adversaries to bend to its will. The nuclear forces were intended to deter the United States and the West from interfering militarily in Russia and its perceived zone of influence. Since the end of the Cold War, Russia’s conventional forces have at times struggled with their share of the task. To compensate, Russian leaders have had to rely on their nuclear forces to do both: strategic nuclear weapons to deter the West and tactical nuclear weapons to threaten neighbors.

In today's situation, a single nuclear strike in Ukraine could thwart a Ukrainian counterattack with little loss of Russian lives. For Moscow, this consideration is as much practical as it is moral or image-related: Last year's large-scale mobilization and increase in military units showed that Putin's army was too small for its task. Nevertheless, Russia has managed to create only a few new battalions because most new personnel and equipment went to replace losses in existing units. Putin and his military leaders are running out of the people and materiel needed to achieve his goals.

Russian military and security experts have been noting this greater reliance on nuclear weapons for years. In 2000, responding to the U.S. bombing of former Yugoslavia, Russian international affairs expert and former lawmaker Alexey Arbatov described how Moscow’s response could be “to enhance its nuclear forces to deter not just nuclear, but also, large–scale conventional attacks of the type demonstrated in the Balkans.” He likewise described a view some say Putin has embraced: that “a suicidal threat of nuclear escalation could present a credible deterrent against a full-scale, theater-wide conventional aggression — including major ground warfare.”

Putin Prepares for a Nuclear Strike

In the first three months of 2023, Putin took several public steps to demonstrate that he is not bluffing about the use of nuclear weapons.

In February, he signed a law “suspending” Russia’s participation in the strategic nuclear arms treaty New START. This step officially ended joint inspections of American and Russian nuclear weapons sites and released Russia from limiting its number of strategic nuclear weapons, Russian promises to remain limited notwithstanding.

In March, Putin announced that he would station tactical nuclear weapons in Belarus this year, building a storage facility to house them, to be completed as early as July. Since Russia has already deployed nuclear-capable Iskander ground-launched missile systems and thousands of troops to Belarus, this would put nuclear delivery systems and warheads in close proximity to one another, greatly reducing the warning time of their use. Putin noted that Russian trainers would also train Belarussian forces to use the weapons. Analyst Dmitri Trenin, former director of the now-defunct Carnegie Moscow Center and a retired Soviet military officer, observed that the Belarus deployment “demonstrates that the conflict between Russia and the West is developing into an armed clash between Russia and NATO, and is a signal to Washington that further American/Western involvement in the military conflict in Ukraine could lead to the use of nuclear weapons.”

Putin has taken these increasingly threatening steps in the belief that NATO and the West — in particular, the United States — are not listening to him as he proclaims Russia’s demands on the international stage. In 2018, when Putin unveiled a bevy of new nuclear weapons, he warned: “You will listen to us now!” Four years later, his invasion of Ukraine was a wakeup call for those in the West who were still not listening.

Even after the invasion though, some in Russia undoubtedly fear that the threat of a nuclear strike has begun to ring hollow. For Putin, whose regime is at risk, in my view, continuing to threaten a tactical nuclear attack in Ukraine without doing it carries perhaps as much risk as doing it. To remind the West of the destructive power of a nuclear weapon, Putin and his generals may decide it is necessary to explode such a weapon. This would enable Russia to escalate the war to its tactical advantage and let Putin prove he is no bluffer.

Besides warning the West many times that he might use a nuclear weapon, Putin and his leadership have, step by step, prepared the Russian people with reasons why he should use nuclear weapons.

Among these justifications, Putin has repeatedly invoked "whataboutist" comparisons to the United States. When announcing plans for deployment of Russian nuclear weapons to Belarus on Russian state television, he said: "The United States has been doing this for decades. They have long … deployed their tactical nuclear weapons on the territory of their allied countries, NATO countries, in Europe, in six states. … We are going to do the same thing." Putin has also several times referenced American nuclear strikes on Hiroshima and Nagasaki and equated American goals then — to save soldiers’ lives and shorten the war — with Russian goals today.

Putin has also made clear to the Russian people that Moscow's red lines for the use of nuclear weapons, spelled out in its official documents, have all been crossed in the conflict in Ukraine. These include “aggression with conventional weapons against the Russian Federation, when the very existence of the state is threatened.” Putin has repeatedly claimed that the very survival of Russia is at stake in the current struggle. At this month's Victory Day parade, he claimed that the West’s “goal is to achieve the collapse and destruction of our country.” He asserts that Crimea and other Ukrainian lands are Russian territory, meaning that, from Putin’s perspective, battles that were occurring on Ukrainian land one day are suddenly happening on Russian land. Another of Russia's officially designated red lines for nuclear use is “attacks … against critical governmental or military sites of the Russian Federation, disruption of which would undermine nuclear forces' response actions.” Russia has claimed that Ukrainian drones have struck Russian strategic nuclear bombers inside Russia, and that Ukraine and the U.S. are responsible for drones launched to assassinate Putin. All these claims, real and fabricated, are used to establish the pretext for Putin to use nuclear weapons when he decides.

Some Western observers of the Russian military claim that because we have not yet seen any movement of nuclear weapons, we have no tangible signs of intent to use them. I disagree.

First of all, last fall, Kyiv officials reported that Russia was firing “Kh-55 nuclear cruise missiles” with dummy warheads. Observers suggested these missiles — which are designed to carry only a nuclear weapon — were launched to erode Ukrainian air defenses by "decoying" them into destroying the Kh-55s rather than missiles with conventional explosives. This claim makes little sense: Missiles, even unarmed, would be too valuable to shorthanded Russia to use as decoys. But launching the Cold War-era missiles with dummy warheads to test their reliability and readiness for use in a real nuclear strike would be a good reason for what we saw.

Another sign of Russia’s increasing readiness to use nuclear weapons is the most recent change in the leadership of the war, which both underscores Putin's message that Russia is fighting for its survival and puts at the helm the very men who are in charge of Russia's tactical nuclear weapons. In January, Putin appointed his chief of the General Staff, Valery Gerasimov, to head the military operation in Ukraine. (Defense Minister Sergei Shoigu said the change was connected to a coming “expansion in the scope of [the war’s] tasks.”) Not since the second world war has the chief of the general staff been in command of a military operation for Russia. Putin also appointed two generals to be Gerasimov’s main deputies in the war, Gen. Oleg Salyukov, head of Russia’s ground forces, and Gen. Sergei Surovikin, head of Russia’s aerospace forces. This is even more worrisome since, under Russian doctrine, the chief of the general staff and the heads of the ground and aerospace forces are the three officers who control all tactical nuclear weapons use in ground operations. Putin has now placed in direct control of the war the three senior-most officers who have the authority to employ tactical nuclear weapons when he gives the order.

When these developments are coupled with the impending deployment of tactical nuclear weapons to Belarus, nearer Ukraine, we can no longer pretend there are no tangible signs of intent.

Trigger for Nuclear Use

With the groundwork laid to justify a tactical nuclear strike in Ukraine, what will trigger Putin’s decision to launch? Most likely it will be the inability of the Russian military to escalate the war by conventional means when Putin demands. For example, if a Ukrainian offensive threatens the loss of Crimea or the provinces that form the land bridge to it, Putin would demand an escalation of the fighting to prevent that loss. If the conventional forces could not successfully respond, however, a nuclear strike against the Ukrainian forces would be the only way to escalate. On the night Putin illegally added four Ukrainian provinces to Russia, he declared, “If the territorial unity of our country is threatened, in order to protect Russia and our nation, we will unquestionably use all the weapons we have. This is no bluff.”

Putin is also under pressure to escalate the war from Russian nationalists. These groups have supported Putin in his rise to power, but now are vocal in their dissatisfaction with the conduct of the war. Some, like former FSB officer Igor Girkin, openly criticize the senior military leadership and even Putin. That criticism may be morphing into opposition, forcing Putin to consider escalating his war before his conventional forces are ready.

Claims that Putin would be dissuaded from using nuclear weapons by important partners like China or India are belied by experience thus far in the war. Although Putin values the support of others, he has not shied from putting that support at risk to get what he wants.

None of this is to say that we in the West should pressure Ukraine to forgo its goal to liberate all seized territory. But it does mean that we should anticipate a nuclear weapon will be used and develop our possible responses accordingly.

Normalizing Nuclear Weapons

As soon as Russia uses a nuclear weapon in Ukraine, the “fallout” will begin and spread. Tens of thousands of Ukrainians will be dead, suffering or dealing with the effects of the nuclear explosion. Hundreds of millions of Europeans will be bracing for war. But 7 billion others around the globe will go about their business, alarmed to be sure, but physically unaffected by a nuclear explosion in Ukraine. This last outcome of a Russian tactical nuclear strike may ultimately be the most dangerous to the international order. The image that many people have of nuclear arms as civilization-ending weapons will be erased. In its place, people will see these weapons as normal and, although tragic, acceptable in war. Just a “bigger bullet.” It is in this dramatically changed context that the United States will have to decide how to respond.

The above text was updated on Aug. 24, 2023, to reflect the following correction: The original version of this article inaccurately claimed that military expert Alexey Arbatov had "advised [in a 2000 paper] that Moscow should 'enhance its nuclear forces to deter not just nuclear, but also, large-scale conventional attacks'" against Russia. In fact, Arbatov, in his 2000 paper, did not explicitly recommend such changes but described them as part of Moscow's evolving response to a perceived threat emanating from the West. In addition, the original version of the above article claimed that Arbatov, in the same 2000 paper, had "predicted a plan some say Putin has embraced: 'a suicidal threat of nuclear escalation [that] could present a credible deterrent against a full-scale, theater-wide conventional aggression — including major ground warfare.'” In reality, Arbatov did not explicitly predict that such a plan would materialize but mentioned it, hypothetically, as part of a debate among Russian military experts. 

Opinions expressed herein are solely those of the author, unless otherwise stated.

Photo shared by the Russian presidential press service (Kremlin.ru) under a CC BY 4.0 license.