Is it all a bluff?
Russian President Vladimir Putin's renewed nuclear threats have raised fears that his plans for escalation in Ukraine may not be limited to mobilizing more troops.
While he has issued apocalyptic threats against the West before, Putin's thinly veiled warnings in a rare national address Wednesday signaled that he was willing to raise the risk of nuclear conflict to avoid an embarrassing military defeat.
The Russian leader accused the United States and its allies of "nuclear blackmail" and said without elaborating that high-ranking officials from NATO states had made statements about the possibility of "using nuclear weapons of mass destruction against Russia."
Then he delivered a notable reminder:
"If the territorial integrity of our country is threatened, we will certainly use all the means at our disposal to protect Russia and our people," Putin said, an apparent reference to Moscow's sizable nuclear arsenal.
"It's not a bluff," he added.
Whether Kyiv and its allies should now be more concerned about the threat was up for debate, analysts said.
"I think it signals that he wants people to think he would risk nuclear war," Phillips O'Brien, a professor of strategic studies at the University of St. Andrews in Scotland. "I don't think it means he is any more likely to do it than he was yesterday."
In his speech in February announcing the start of what the Kremlin calls its "special military operation" in Ukraine, Putin warned that anyone who dared to intervene would face the full force of Russia's nuclear arsenal.
This time, however, he faces a different reality: His army has experienced humiliating setbacks, his troops are demoralized and depleted, and he's facing rare criticism at home.
Desperate for a victory, the Russian leader allied his nuclear threats and call-up of reservists to a plan to annex occupied territory in Ukraine's east and south.
"He is doubling down politically because he is losing militarily," said Michael Clarke, professor of war studies at King's College London. "Creating more 'Russian' territory is an attempt to scare the West because Russian nuclear doctrine has always maintained that nuclear weapons would only be used in defense of Russia directly. He says, 'This is not a bluff,' which shows that it is."
While the country's military doctrine limits the use of nuclear weapons to direct threats to the existence of the Russian state, observers noted that in his address, Putin used the ill-defined term "territorial integrity" when talking about what conditions would merit a nuclear response.
Seemingly extending the conditions for possible nuclear use in the middle of a war, and just as Russia is planning to absorb four Ukrainian regions, means Putin had "boxed himself in," analysts said.
"If Ukraine continues to try and liberate its own territories after a referendum has occurred, a sham referendum, does that mean he's going to attack right away?" O'Brien, the strategic studies professor, said. "I think he has sort of boxed himself in with this. It's certainly aggressive rhetoric, but it's not necessarily intelligent policy."
Kyiv has already indicated that Russia's attempts to annex new territories change nothing and vowed its military will keep pushing on the battlefield. President Volodymyr Zelenskyy was also skeptical Wednesday that Putin would use nuclear weapons.
Washington largely brushed off the threats as irresponsible but nothing new, though NATO Secretary-General Jens Stoltenberg denounced Putin's "dangerous and reckless rhetoric."
While they may not be a precursor to nuclear warfare, O'Brien said Putin's threats should be taken seriously considering Moscow's capabilities.
"But I think it should also not be, 'We are going to end up with the end of the world,'" he added.
In fact, when Ukraine launched attacks on annexed Crimea this summer, a territory Moscow considers Russian, Putin did not reach for the nuclear button, O'Brien noted.
"If he says that any attack on soil that he calls Russia is going to be a nuclear tripwire, Ukraine's already broken that in Crimea," he added.
Putin may also be trying to dissuade Western countries, including the U.S., from supplying Kyiv with more of the weapons it has used to such potent effect on the battlefield, said Keir Giles, a Russia expert and senior consulting fellow at Chatham House, a London think tank.
"Putin's speech is full of indicators that he recognizes Russia has been unable to defeat Ukraine on the battlefield, so it has to look for victory elsewhere. And that victory, Putin hopes, could come through eroding Ukraine's international support," Giles said. "That is why Russia is daring the West to support Ukraine further, and appealing to the most fearful and timorous among Western leaders, particularly those who are most susceptible to Russia's repeated nuclear threats."
Pro-Kremlin voices have delighted in Putin's escalation, which comes after months of state media coverage dominated by talk about the possibility of nuclear strikes on European capitals.
As Russian plans to annex new Ukrainian territory emerged Monday, one of the Kremlin's top propagandists declared: "This week marks either the eve of our imminent victory, or the eve of nuclear war. I can't see a third way."
Neither, apparently, can Putin.
This article was originally published on NBCNews.com