Ukraine is racking up wins in its battle against Russia, pushing Kremlin forces out of occupied towns in the northeast and breaking through enemy lines in the south.
Russian President Vladimir Putin is losing his war, and his frantic efforts to regain momentum through conventional means are destined to fail, according to defense experts and Western officials.
However, pushing Putin into a corner could be far more dangerous than the grinding fighting playing out now, if he turns to nuclear weapons or other extreme measures.
"It's highly likely that he will try risky things in order to pull a miracle out of his hat and get a victory big enough" to sell to the Russian public, said Hein Goemans, a political science professor at the University of Rochester who studies how wars start and end.
What those actions might be - and what a "big enough" victory would look like - are fodder for high-stakes speculation. But Putin needs more than what he has now to have a chance of staying in power, Goemans said.
"If he comes home with what he has now, he probably will be removed and killed. … There's no happy ending for him out of office," he said.
After Russian forces were routed in a Ukrainian counteroffensive last month, Putin responded with a nationally televised speech announcing the mobilization of up to 300,000 military reservists and setting in motion the annexation of four occupied regions in Ukraine.
He framed those annexations as a victory in a grand ceremony last week, but has since lost occupied territory in Donetsk province in the east and Kherson province in the south, both of which are among the regions newly claimed by Moscow.
"The Kremlin's armed forces are disintegrating before our eyes, demoralized (literally) by their bad leadership, botched planning, and poor logistics," Edward Lucas, a security specialist at the Center for European Policy Analysis, wrote this week.
Military experts say Putin's latest push to send reinforcements to Ukraine is unlikely to turn the tide against Ukraine's well-organized, well-equipped and determined forces.
"What Russia is doing won't give you a military formation. It'll give you just a bunch of men with weapons, if they work on the battlefield, trying to respond to that level of military superiority," John Spencer, an urban warfare expert at West Point, told Forces News.
However, Russia still controls large swathes of Ukraine - including Crimea, which it seized in 2014 and remains a key staging ground for its invasion - and Putin has proven willing to tolerate staggering casualties.
"There's probably a lot of fighting that still remains," former Defense Secretary and CIA Director Leon Panetta told CNN on Wednesday. "My intelligence friends all make clear that Putin will continue to double down. And ultimately what that means is that we are still going to have a prolonged war in the Ukraine."
Panetta argued that the longer Putin remains in Ukraine, the harder it will be for him to find an off-ramp that allows him to save face.
"If he is totally defeated, then I don't see any way that Putin can survive in Russia. So the real question is whether Putin wants to survive, or whether he wants to ultimately end his regime," Panetta said.
However, for Putin to claim a credible victory he would likely need to extract some territorial concessions from Ukraine, and that is unlikely as long as Kyiv continues to feel optimistic about its chances of eventually ousting Russia.
Tech billionaire Elon Musk tweeted a peace proposal this week suggesting Ukraine should agree to elections to decide the future of the annexed territories, officially cede the occupied Crimean Peninsula to Russia and agree not to join NATO.
"This is highly likely to be the outcome in the end - just a question of how many die before then," he wrote. A Ukrainian diplomat promptly told Musk to "f- off," and Kyiv accused him of parroting Kremlin talking points.
Ukrainian President Volodymyr Zelensky's own political credibility depends on his refusal to make the concessions that Putin would need to claim victory and retreat.
"Even if Zelensky were to [accept] some concessions, and there's no evidence that he's willing to, but even if he were to try, it's very likely that the people will actually get rid of him. They will not tolerate it," said Branislav Slantchev, a political science professor at University of California, San Diego, who studies military coercion and intra-war negotiations.
He noted that recent polls show more than 90 percent of Ukrainians said they would refuse to consider the swap of any land for peace.
On the battlefield, Ukraine appears to be trying to liberate the city of Kherson before winter and then advance to Russia's only land bridge across the Dnieper River, Slantchev said. Should it take that bridge, Ukraine would cut off some 25,000 Russian forces from their only supply route.
"So every day I celebrate the Ukrainian advances I get more and more nervous, because that pushes Putin further and further into the corner that he created himself," he said. "If the front on the right bank of the Dnieper River collapses for the Russians, he might actually use nuclear weapons to kind of scare everybody to force them to stop at least to prevent the full collapse."
Slantchev said the initial nuclear strike would likely be relatively limited and targeted at military positions, rather than an attack on a population center, which would be more likely to elicit a stronger NATO response.
"So I believe he's going to use something that is some sort of demonstration and bank that the West will not actually be able to respond to this. I still think he's trying to scare us," he said.
The U.S. has promised "catastrophic consequences" if Russia deploys nuclear weapons, and officials say more concrete warnings have been delivered discreetly to the Kremlin, in an attempt at deterrence.
However, defense experts say it is highly unlikely that the U.S. and NATO respond to nuclear aggression with a nuclear counterattack. Instead, they expect the West to double down on its support of Ukraine's military, possibly deliver symbolic strikes to Moscow's Black Sea fleet and pressure key Moscow allies like China and India to isolate Russia economically.
The U.S. will almost certainly avoid moves that could escalate the war further, said Dan Goure, a security expert and vice president of the public policy think tank Lexington Institute.
Apart from an attack on a NATO country, Goure said the Biden administration has not drawn a clear red line regarding Russian actions in Ukraine, which is not a member of the alliance.
Goure argued in National Interest this week that the long-feared "possibility" that Moscow would resort to using nuclear weapons "has now become a virtual certainty," in part because Putin believes he can get away with it.
"I think he's got a weak hand and this may, in his mind, at least, strengthen it across the board," Goure said Thursday. "At least domestically, it becomes a victory in itself. 'Look what I was willing to do to protect the Russian people, the Rus writ large. You know, I told you I was serious about this. I'm really serious about this, and getting away with it.'"
Between conceding defeat and using weapons of mass destruction, there is a third option: continuing the pounding conventional war and hoping that Moscow's larger military can outlast Ukraine and its Western allies.
The Washington Post reported Thursday that Russia's recent retreat in the crucial southern region of Kherson appeared far more strategic than its frantic flight from Kharkiv in the northeast, suggesting that Moscow is digging in for a long fight.
Goemans said Putin may try to maintain the bloody status quo for months or years, pushing a narrative that Russia is winning, delivering occasional setbacks to Ukrainian forces, hoping that political conditions change in Europe or the U.S. - and sending many more Russian troops to die.
"I want Putin to, quote-unquote, lose, but my heart also goes out for these Russian soldiers. Just getting slaughtered for nothing - boots without guns. It's like World War I. People walk after each other in the hope that if the guy gets shot, they can pick up their gun," he said. "I mean, it's just so awful."
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