Ever since his invasion of Ukraine, Russian President Vladimir Putin has repeatedly reminded the world of the most dangerous weapons at his disposal. Now, for the first time, a report suggests that top Russian military leaders have discussed when and how they might use a tactical nuclear weapon in Ukraine.
According to the New York Times, senior U.S. officials learned of these conversations in mid-October. The officials said that Putin was not involved in the discussions, and they would not describe specific scenarios the Russian leaders had considered.
The report lands at a particularly tense moment in the war.
Battlefield setbacks and an emboldened Ukrainian resistance have shut down — for now — any negotiations to end the war, narrowing the list of potential endgames. As Grid’s Joshua Keating reported last week, the current trajectory of the conflict makes it hard to imagine any scenarios other than “a coup or a nuke” — meaning Putin will either be overthrown or use every means at his disposal to avoid defeat. And the new intelligence comes to light as the Kremlin has been promoting baseless claims that Ukraine plans to use a so-called dirty bomb — a conventional explosive laced with radioactive material; American and other officials fear Russia might use that false claim as the pretext for a nuclear response.
What might compel Putin to use a nuclear weapon? What sort of strike might he employ? How might he be deterred? And if he were to turn to this last-ditch, and paradigm-shifting, tactic, how would the world respond?
Here’s what we know.
What Putin has said
Russia’s president has made repeated, not-so-subtle references to Russia’s nuclear arsenal and his willingness to use it. The first warnings came before Putin sent his troops into Ukraine.
On Feb. 19, the Russian president personally presided over strategic nuclear exercises, including the launch of ballistic missiles; five days later, in his declaration of war, Putin made a point to threaten any outside countries that might “hinder us, and … create threats for our country” with “such consequences that you have never experienced in your history.”
The message was plain: If you interfere, you risk nuclear war.
On Feb. 27, Putin took things a step further. He announced that he was placing Russia’s nuclear forces on high alert, in response to economic sanctions imposed on his country and what he called “aggressive statements” by NATO leaders. It marked the first time either Russia or the U.S. had raised its nuclear alert level since the U.S. did so during the Arab-Israeli Yom Kippur War, nearly a half century ago.
In the months since, Putin’s warnings have tended to come in the wake of bad news on the battlefield. In a late-April speech in St. Petersburg, given as NATO heavy weaponry bolstered the Ukrainian resistance, Putin said, “If anyone decides to meddle in ongoing events and create unacceptable strategic threats for Russia, they must know our response will be lightning-quick. We have all the instruments for this, ones nobody else can boast of. And we will use them, if we have to.” And in September, after heavy losses in northeast Ukraine, Putin ordered sham referendums that led to his annexation of four regions in southern and eastern Ukraine — and vowed to defend these new territories with “all the means at our disposal.”
The words “instruments” and “all the means at our disposal” were understood as thinly veiled references to Russia’s nuclear arsenal.
Last week, for the first time since the war began, Putin turned down the nuclear temperature. In an address to the nation, he insisted he had no intention of employing the nuclear option.
The Kremlin “never said anything proactively about the possible use of nuclear weapons by Russia,” Putin said. “We see no need. There is no point in that, neither political nor military.”
The Russian arsenal — and “tactical nuclear weapons”
Russia has the world’s largest nuclear arsenal, with 1,458 strategic warheads deployed on 527 intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles and strategic bombers, as well as a stockpile of almost 5,000 more warheads. Virtually the entire world is in range of its most advanced ICBMs.
But experts don’t believe these warheads and long-range delivery systems are relevant to the current situation. For a number of reasons, the analysis — speculative and hypothetical as it is — focuses on Russia’s possible use of what are known as “tactical” nuclear weapons.
As Keating has reported, the term “tactical” is often used to imply that a bomb is smaller or less powerful, but this can be misleading. Some “tactical” warheads in the U.S. arsenal have yields of around 100 kilotons. That’s smaller than some of the larger bombs available today, but still massive: The bomb the U.S. dropped on Hiroshima had a yield of just 15 kilotons.
In the current conversation, “tactical” nuclear weapons are distinguished from the “strategic” variety, but the difference has less to do with the bombs themselves than how they would be used. Strategic warheads typically refer to those which nations might fire at one another’s civilian population centers in the event of an all-out nuclear war; the bombs dropped on Hiroshima and Nagasaki — still the only uses of nuclear weapons in history — were the textbook examples.
A “tactical” weapon, on the other hand, would be used for some specific gain in a war zone.
“A tactical nuclear weapon is basically a weapon that you would use to gain advantage, get some advantage on the battlefield or on the theater of operations,” Pavel Podvig, an expert on Russia’s nuclear forces at the United Nations Institute for Disarmament Research, told Grid.
In the case of Ukraine, a tactical nuclear weapon could be used to destroy an airfield, an enemy tank column or other large military target.
According to recent estimates, Russia may have between 1,000 to 4,000 of these tactical weapons, which are generally thought of as having shorter range and carrying lower explosive yields. Again, “lower yield” is a relative concept. The yield of Russia’s tactical nuclear weapons is believed to range between 10 kilotons to 500 kilotons of TNT; the Hiroshima and Nagasaki bombs were on the low end of that range.
Why would Putin use a nuclear weapon?
This is of course the most important question, and the answer is best understood in the context of that narrowing number of potential endgames in Ukraine.
Repeated battlefield successes have emboldened Ukrainian President Volodymyr Zelenskyy, and every Russian atrocity has eroded interest among Ukrainians in making any concessions to Moscow. On the other side, Putin is under withering criticism from Russian hardliners who have supported his “special military operation” but want it prosecuted more effectively and with greater ferocity. These criticisms often include crude exhortations to the Kremlin to use nuclear weapons against Ukraine.
Taken together, entrenchment on both sides has left no room — for now at least — for a diplomatic solution. That in turn increases the possibility — slim though it may be — that Putin would resort to the nuclear option.
In that October speech in which he dialed down the rhetoric, Putin referred to Russia’s military doctrine, which states that nuclear weapons must only be deployed defensively. The doctrine guarantees, Putin said, that Russia would use them only “to protect its sovereignty, territorial integrity and to ensure the safety of the Russian people.”
If it was reassuring to hear a softer line, it was also worth remembering that Putin used those same justifications — sovereignty, ensuring the safety of Russians, etc. — to explain his invasion of Ukraine. In other words, he could argue tomorrow that those circumstances exist and thereby warrant the nuclear option.
The will-he-or-won’t-he nuclear question can be put differently: What happens when a nuclear power is backed into a corner? Would Putin really allow his military to be defeated on the battlefield without using every weapon at his disposal?
In a September piece for Grid, former Russian journalist Stanislav Kucher cited a story Putin has told about a childhood experience, when the future president cornered a rat with a stick in the stairwell of his apartment building. The animal lashed out and began chasing him. As Kucher wrote, the analogy today is that with his forces collapsing on the battlefield, Putin may feel himself backed into a corner, with no face-saving off ramps and a perceived threat to his hold on power.
In such a scenario, the proverbial cornered rat may lash out with a horrific attack that would be the Russian leader’s last-ditch effort at forcing Ukraine to surrender.
The potential impact
Without knowing the size or location of any nuclear attack on Ukraine, any assessment of the impact is necessarily imprecise.
This much we know: Even a small nuclear explosion could cause thousands of deaths and render parts of Ukraine at least temporarily uninhabitable.
If used on the battlefield, a tactical nuclear weapon might be fired in airbursts over enemy forces to spread its effects. This would maximize casualties among lightly entrenched Ukrainian positions, in theory, and cause less radioactive fallout (by blasting less contaminated soil into the fallout plume) that could blow back onto Russian-held territory.
A “small” 10-kiloton blast of this kind would demolish buildings in a 0.4-mile radius around its center and cause fatal radiation sickness to anyone 0.78 miles away, according to nuclear historian Alex Wellerstein’s NukeMap blast simulator. A mushroom cloud some 3.5 miles high would spread over a crater almost the size of a football field.
Casualties from the blast would vary greatly depending on the location. Such a detonation on the outskirts of Kherson, where Ukrainian forces are now advancing, would immediately kill and injure hundreds of people, depending on how concentrated Ukrainian troops were at the location. The same blast over central Kharkiv might kill 50,000 people and injure another 100,000 — a toll similar to the one at Hiroshima. People within the fireball radius, roughly the width of a football stadium, would be instantly incinerated, while others would die from radiation, burns and other injuries.
Higher-yield weapons would carry even more destructive impact. Detonation in sparsely-populated areas — carried out perhaps with the aim of warning that worse could be coming — would do less damage.
Survival outside the fireball and radiation zones of any nuclear blast would also depend on the nature of shelter for the population. Even a 10-kiloton blast would flip cars a mile away and collapse light structures. People in a several-mile radius would suffer flash blindness, ruptured eardrums and injuries. Fire would likely kill people trapped in collapsed structures. Radiation sickness, its lethality related to distance from the explosion, would kill more people within days to weeks after the blast.
Tens of thousands of people died after the Hiroshima and Nagasaki blasts from all these kinds of injuries. Again, much would depend on the population of the affected area.
How the U.S. and NATO might respond
The White House, the Pentagon and their European counterparts have no doubt been gaming out such scenarios and potential responses to any Russian nuclear strike.
The U.S. and Ukraine’s other Western allies would be under pressure to respond in kind, but a nuclear response to a nuclear strike would risk almost unimaginable chains of escalation. President Joe Biden and other senior U.S. officials have warned publicly that the American response would be “consequential.” None of them have elaborated on what that might mean.
Asked in a September “60 Minutes” interview about the possibility that Putin would use the nuclear option, Biden offered a blunt message.
“Don’t. Don’t. Don’t,” the president said. “It would change the face of war unlike anything since World War II.”
Former CIA official and Grid Special Contributor John McLaughlin wrote recently that the U.S. response “would depend on factors such as where Putin strikes, and with what kind and yield of weapon (ground attack or air detonation, e.g.).”
There would be no shortage of potential retaliation targets, McLaughlin said, ranging from Russian supply depots to Black Sea bases and others.
But he and others have also noted that the U.S. response could — and in McLaughlin’s view, should — be conventional. The U.S. “would not have to ‘go nuclear,’” McLaughlin said, “to make its point in a devastating way.” Former CIA director Gen. David Petraeus has suggested that a conventional response need not be “nuclear for nuclear” but should include the option of “taking out” Russian forces with conventional military strikes.
McLaughlin also cautioned against an immediate response. “Condemn the act in the most serious terms,” he argued, “but hold any retaliation long enough to let the world and [Putin’s] fellow Russians absorb what he has done. How long to hold fire would depend partly on how the world reacted; for one thing, a Russian nuclear attack would confront China and Putin’s other enablers — all of whom oppose any ‘first use’ of nuclear weapons — with an act they would almost certainly deplore and probably condemn outright.”
All that said, once a nuclear weapon is used, there is no scenario in which a rapid and frightening escalation can be ruled out.
If there are slivers of good news here, they are these:
First, there is the fact that despite Putin’s regular bluster — even the order to place his nuclear forces on “high alert” — the world has seen no concrete signs that preparations have been made for their use. That of course could change overnight; but it hasn’t happened yet.
Then there is a more subtle point, which Keating and McLaughlin and others have made. Namely, that for all his anti-Western rhetoric, the Russian leader shows no interest in a direct military conflict with NATO. And the surest way to start such a conflict would be to use a nuclear weapon.
Despite his rhetoric and warnings, Putin has not even used conventional weapons against NATO weapons depots or shipments. The Kremlin could have construed these as Western “interference,” the word he used in his initial warnings to the West. And when Putin annexed four regions in eastern and southern Ukraine, there were fears that he would now consider Ukrainian military presence in those areas cause for a massive — even nuclear — response. But for all the brutality of the Russian assaults on Ukraine, Putin still appears to be doing what he can to avoid any direct military engagement with NATO.
In the end, it will be Putin and Putin alone who determines what constitutes a threat to his state — or to his leadership — and whether those threats are worth making what would be a fateful and terrifying decision.
As Shannon Bugos, a senior policy analyst at the Arms Control Association, told Grid, “A nuclear weapon is a nuclear weapon. Once you’ve introduced a nuclear weapon onto the battlefield, that’s the endgame. There’s no coming back.”
Thanks to Alicia Benjamin for copy editing this article.