President Vladimir V. Putin of Russia accelerated his war effort in Ukraine on Wednesday, announcing a call-up of roughly 300,000 reservists to the military, while also directly challenging the West over its support for Ukraine with a veiled threat of using nuclear weapons.
In a rare address to the nation, Mr. Putin said he was prepared to declare four Ukrainian regions to be part of Russia as early as next week, even though some of that territory is still controlled by Ukrainian forces. And he framed the war he launched seven months ago in existential terms for Russia, insisting that the nation was merely defending itself against a mortal threat to its “sovereignty” and that the West was seeking to “weaken, divide and ultimately destroy our country.”
“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,” he said. “This is not a bluff.”
Taken together, Mr. Putin’s speech laid out the Kremlin’s strategy of continuing to raise the stakes in the war, despite the humiliating setbacks Russia’s military has suffered on the battlefield and a potential public backlash in Russia. Protests against the mobilization and arrests were reported in dozens of cities.
The address also suggested that even as Mr. Putin was mobilizing more troops, his broader aim was to startle the United States and its European allies into dropping their support for Ukraine or compelling President Volodymyr Zelensky to negotiate a peace deal that is acceptable to Moscow.
“You get the feeling now that he might do anything, and this is his strategic potential,” Gleb O. Pavlovsky, a Moscow political analyst and a former adviser to Mr. Putin, said in a phone interview. “He is using this strategic potential because he has no other.”
Russian occupation authorities in four Ukrainian regions declared on Tuesday that they would stage referendums on annexation by Russia, laying the groundwork for Mr. Putin’s escalation. In his speech on Wednesday, he said he would support the results, likely redefining the territory as part of Russia, while justifying the mobilization as a matter of self-defense.
But if Mr. Putin’s aim was to change the terms of the war so profoundly as to shake Ukraine and its allies, there was no immediate evidence that it was working.
In Kyiv, Mr. Zelensky told a German newspaper in response to Mr. Putin’s speech that the Russian president wanted to “drown Ukraine in blood” and that he would only negotiate “if they leave our territories.” Olaf Scholz, the German chancellor, said in an interview with The New York Times that the situation was “dangerous,” but that Russia’s status as a nuclear power would not “change what we are doing.”
At the U.N. General Assembly in New York on Wednesday, President Biden insisted that “we will stand in solidarity to Russia’s aggression,” and said Mr. Putin was making “irresponsible nuclear threats.’’ He added later, “This war is about extinguishing Ukraine’s right to exist as a state.”
In Russia, the announcement of a major call-up thrust the Kremlin into uncharted political terrain. Until now, the government has sought to assure regular Russians that they could go on living their lives, referring to the war as only a “special military operation” and insisting that no one would be forced to fight in Ukraine against his will.
But this month’s stunning counteroffensive by Ukrainian forces, in which Kyiv retook more than one thousand square miles of territory, appeared to change that calculus. Mr. Putin suddenly appeared on the back foot, under fire from even some of his supporters on national television who claimed that he was not waging war decisively enough. And the fact that Russia lacked sufficient combat personnel in Ukraine to make gains or even to hold territory — as Western analysts and officials have asserted for months — became unmistakable.
In response, Mr. Putin declared for the first time on Wednesday that Russian civilians could be pressed into service in Ukraine. Apparently keen to avoid a public backlash, the Russian leader insisted that the new draft was only a “partial mobilization” and that only men with military experience would receive orders to report for duty.
Mr. Putin said that Russia’s goals in Ukraine had not changed and that the move was “necessary and urgent” because the West had “crossed all lines” by providing sophisticated weapons to Ukraine.
In subsequent remarks, Russia’s defense minister, Sergei K. Shoigu, put the number of potential new call-ups at 300,000 people. He said that university students would not be subject to the draft, and that young conscripts serving the one year of military service that is required in Russia would not be sent to the front lines.
But the official order declaring the call-ups was far more vague, leaving open the possibility that the government could later broaden the draft.
In Russia, news of the call-up spurred protests across the country; more than 1,200 from 38 cities were detained, according to OVD-Info, a human rights watchdog that monitors police activity. In Moscow, hundreds of protesters gathered on the Old Arbat, a pedestrian street in the city center, screaming “Send Putin to the trenches!” and “Let our children live!”
Some Russians rushed to purchase plane tickets out of the country, and the Telegram messaging app was filled with messages about the border situation and possible ways to get out of the country.
The responses underscored the risks being taken by Mr. Putin as he pushed to escalate a war that has caused heavy Russian casualties and is increasingly violating his unspoken deal with the public: that Russians stay out of politics and the Kremlin lets them live their lives. Mr. Putin has successfully clamped down on dissent since starting the war, with new censorship laws and a spate of arrests, but analysts said that the main reason he long avoided declaring a draft was his fear of public backlash.
“This is crossing a red line,” Mr. Pavlovsky, the former Putin adviser, said, referring to Wednesday’s mobilization order. “It will violate, in a sense, the contract with the Putin majority.”
Military analysts said the draft would not have immediate consequences on the battlefield because it would take weeks, if not months, for Russia to mobilize, train and equip additional combat-ready troops. Still, the move could begin to address Russia’s manpower shortages, in part because it would prohibit existing contract soldiers from quitting, said Michael Kofman, director of Russia studies at the CNA defense research institute in Arlington, Va.
Mr. Putin this week has also sought to retake the initiative by setting the stage for claiming sovereignty over more territory in Ukraine. Russian occupation authorities in Ukraine said they would hold five-day, snap “referendums” starting Friday on joining Russia, a likely prelude to annexation.
“Russia can’t give up on people living close by to be torn apart by executioners and fail to respond to their desire to determine their own fate,” Mr. Putin said, referring to Ukrainians in occupied territory, even as reports continue to emerge of torture and killings by Russian occupying forces.
Pro-Kremlin analysts and officials have said that after annexation, Moscow could claim that any further Ukrainian military action on those territories was an attack on Russia itself, providing Mr. Putin with a justification for retaliation. He did not explicitly threaten a nuclear response, but warned that he was ready to use all of the weapons in Russia’s arsenal to protect what the Kremlin considered Russian territory.
“An attack on the people and territories will be an attack on Russia,” a senior Russian lawmaker, Konstantin I. Kosachev, posted on social media, warning the West to “stop playing military games with a nuclear state.”
Western officials have condemned the planned referendums as “sham’’ votes, and Ukrainian officials have described them as a red line after which negotiation with Russia would be impossible.
But there remained some signals that Mr. Putin was open to a negotiated exit from the war.
Hours after his speech, officials in Kyiv announced that Russia had released 215 Ukrainians in a prisoner of war exchange, including the top two commanders of the Azov Battalion and more than 100 other troops who were involved in the last-ditch defense of Mariupol before it fell to the Russians in May — fighters who are regarded in Ukraine as national heroes. Saudi Arabia made its own announcement about an exchange that secured the release of 10 prisoners held by Russia, including U.S. and British citizens.
Andrei Kortunov, director general of the Russian International Affairs Council, a research organization close to the Russian government, said in a phone interview that he did not expect Mr. Putin to use nuclear weapons in Ukraine as long as NATO did not directly attack Russia. Doing so would offer no significant battlefield advantage over conventional weapons, he said, while “the political risks associated with this are very high.”
Mr. Kortunov said that Mr. Putin’s goal was now pressuring the West, rather than Ukraine, to agree to some kind of peace deal.
“This means that there is no hope for political dialogue with Kyiv,” Mr. Kortunov said of Mr. Putin’s apparent plans for annexing more of Ukraine. “If there is any dialogue, it will be with the West, not with Kyiv.”