Over seven months in, it’s perfectly understandable that many are not following every thrust and parry in Russia’s invasion of Ukraine. Vladimir Putin assumed that Russian forces could stroll into Ukraine in a “three-day war” that ended with his troops goose-stepping down the streets of Kyiv. He was wrong. The war that has developed is one in which the real contest is simply this: How many people will Russia murder in the name of goals they cannot possibly achieve?

You don’t have to know the difference between Novovoznesenske and Novovoskresenske, or what it takes to erect a pontoon bridge, to understand that Russia is losing, the territorial gains they made in the early days of fighting are being rolled back, and the reputation of the Russian military has been absolutely wrecked. Putin started a war he can’t win, but he’s only begun to grasp how much he can lose.

In response, Putin has made two moves. First, he announced what he described as a “partial mobilization” of military reserves, but which actually represents national conscription of men from 18 to 60 (and older). Second, he’s conducted a series of “referenda” in occupied areas to justify absorbing those areas into Russia.

Both of these are setting up a third move that seems increasingly possible: a tactical nuclear strike.

Right this moment, despite the lack of general attention it’s getting, the world may be at a greater risk of a nuclear weapon being used in war than at any time since World War II. That includes the Cuban Missile Crisis and anything Kim Jong Un has done.

On Sept. 30, Putin is scheduled to give a speech. At that time, he’s planning to announce that his fake elections show overwhelming support in the occupied regions for joining the Russian Federation. Russian officials in charge of those occupied areas—Luhansk, Donetsk, and Zaporizhzhia—have already been flown to Moscow, where they are expected to present “applications” to make their territories part of Russia. Putin will accept these applications and immediately declare that these areas are now Russian territory.

This is important, not just because it throws Putin something he can claim as a “win,” but because of certain rules written into the Russian constitution. One of those is that conscripted military can only be used in the defense of Russian territory. The second is that the Russian constitution forbids first use of nuclear weapons except in direct defense of the Russian Federation.

By passing his fake referendums, Putin both justifies using his “mobilized” forces in Ukraine and opens the door to the use of nuclear weapons. In particular, tactical nuclear weapons. Putin has underlined this repeatedly by making it clear that, following his announcement, any military action on the territories covered by the referenda will be “considered an attack on Russian territory.”

In addition, this week saw the sabotage of the Nord Stream 1 and Nord Stream 2 gas pipelines. The near-universal conclusion of everyone who has looked into this is simple: Russia did it. But the why of the pipeline bombing is not reassuring.

Russia didn’t just blow the pipelines because it would give Tucker Carlson another reason to claim that President Joe Biden is part of some international conspiracy. The pipeline was bombed because it gave Russia a grievance. And the politics of grievance are 99% of what drives action in Moscow. On Russian television, that pipeline is a powerful symbol of Russia’s “us against the world” mentality.

Blowing up their own pipelines, even pipelines that no longer represent much economic value, may seem incomprehensible to those outside of Russia. But it’s excellent domestic politics.

As historian and analyst Kamil Galeev explains, the Kremlin “may view a nuclear strike on Ukraine as a rational move,” even if that move comes with a guarantee of a retaliatory strike from the United States. In fact, that retaliation may be an important part of what makes this effective “in the context of domestic policy.”

For Galeev, who has provided invaluable insights throughout the invasion, it boils down to this: Putin now realizes that he has picked up a red-hot potato in the form of Ukraine. He wants to put it down. But he doesn’t want to lose power in Russia.

Many argued that Putin should be allowed to “save face”. The thing is: it is nearly impossible for him to save face at this point. Inability to crush Ukraine is already a loss of face, no matter how you frame it. For a simple reason that Ukraine had been considered an inferior. The very idea that Ukraine can stand its ground against Russia would have been considered totally insane at the start of this year, both in Russia and outside of it. The fact that it does means that Putin has already suffered a major loss of face, and will continue suffering it.

So what does Putin do? Engage the United States in the war, so that any loss is not a loss to Ukraine, but to “all the Western powers” combined.

The Russian public realizes that the U.S. is more powerful—both militarily and economically—than Russia. If Putin can goad the U.S. into a retaliation, even one that represents a large loss for the Russian military and a forced withdrawal from Ukraine, for Putin, this could be seen as a win. Anything short of the U.S. literally moving into the Kremlin will be seen as proof that Putin outfoxed the West.

But how to make that happen? President Biden has been very careful in taking steps that would be seen as the U.S. directly involving itself in this war. That includes a flat declaration that there will be no U.S. “boots on the ground” in Ukraine. Ukraine may get U.S. weapons, it may get U.S. training, but it’s not getting the direct support of the U.S. military.

Unless…

The use of a nuclear weapon is the one thing that Putin can do that is almost guaranteed to draw a direct U.S. military response. Ukrainian military intelligence now reportedly believes that the odds of Russia following this course of action and using a tactical nuclear weapon inside Ukraine are “very high.”

What would the use of a tactical nuclear weapon look like? Tactical nuclear weapons are designed for use against a specific enemy, rather than in a massive and apocalyptic strategic nuclear war. They range in size from around 1 kiloton to 50 kilotons, rather than the megatons of destruction in a strategic nuke. However, that scale is not very reassuring when it’s considered that the weapons which destroyed Hiroshima and Nagasaki were in the 15 kiloton range.

Russia has a staggering number of these weapons, around 2,000. Russia doesn’t view these weapons the same way that many in the West see all nuclear weapons. For Russia, these weapons are a matter of pride, and both military and political figures have spent decades playing up the idea that it is exactly these weapons that have prevented NATO from marching to Moscow. The use of a nuclear weapon does not carry the same idea of being taboo as it does for other nations. Putin choosing to use such a weapon is unlikely to be seen as a failure, or as beyond the pale, by most Russians.

It’s exactly Russia’s refusal to negotiate a reduction of these weapons that has blocked most recent efforts to further limit nuclear weapons. How many are still viable isn’t clear, but it should definitely be assumed that number of greater than one. And one could be all it takes.

There’s very little way in which using a tactical nuclear weapon in Ukraine would benefit the Russian military. Putin might well choose to bomb the area of eastern Donetsk where the Russian military has made such slow progress over the last months. This could possibly destroy a sizable number of Ukrainian troops, along with thousands of civilians, but it would not allow Russian forces to actually march in and capture the territory.

Russia might also choose to use a nuclear weapon against a Ukrainian city—Kyiv, Kharkiv, or Odesa. They could generate an enormous death toll, but even for a nation that has become so good at finger-pointing when another mass burial or torture chamber is discovered, this would be such an obvious crime it would be impossible to deny.

In the invasion of Ukraine, Putin has already isolated Russia from the family of nations and is widening that division by the day. The use of a nuclear weapon would open such a chasm, it might be generations in closing. But again, that might not matter to Putin, so long as it solidified his position at home.

What form might a U.S. retaliation take? That’s unclear. A surprising number of military experts seem to believe a response might come in the form of destroying Russia’s Black Sea Fleet. That’s something that could happen without technically making a strike on Russia, but would still be a highly consequential action. As Blinken notes, the U.S. surely has plans, and those plans are likely to scale according to just what kind of action Russia takes.

How likely is it that Putin will actually press that button? Each loss in Ukraine may make it more likely, but at the same time, it’s not as if Ukraine, or the nations assisting Ukraine, can sit back and let Putin win just because he might do something terrible. He’s already doing something terrible, and the bodies at Bucha and Izyum, along with the rubble that remains of Mariupol, bear witness to that fact. It’s not even clear that if Putin chooses to use a nuclear weapon, it will be more awful than what’s already happening. It will just be differently awful. And it will almost certainly put an end to this war—with Russia losing everything.