Stalled by Ukrainian forces, where does Putin go from here?

WASHINGTON — Russia President Vladimir Putin's war in Ukraine is approaching a new phase after a month of fighting has left Russian forces stalled by an outnumbered foe.

He is left with stark choices how and where to replenish his spent ground forces, whether to attack the flow of Western arms to Ukrainian defenders, and at what cost he might escalate the war.

In what could signal an important narrowing of Moscow's war aims, the United States said Russian forces appear to have halted — at least for now — their ground offensive aimed at capturing the capital, Kyiv, and are concentrating more on gaining control of the Donbas region. The Donbas is the largely Russian-speaking eastern part of the country where Russian-backed separatists have been fighting Ukrainian forces since 2014 and where many residents desire close ties to Moscow.

But at the same time, Russia has begun to mobilize reinforcements as its combat losses continue to grow, the Pentagon said Friday.

"We now have indications that they are drawing on forces from Georgia," said a senior U.S. defense official. Thousands of Russian troops are regularly stationed at outposts from Georgia to Syria to Tajikistan, many of them in motorized rifle brigades that experts consider combat-capable and ready to deploy immediately.

"I'm not sure that anything that the Russian military will do will change the balance; it's more about patching up gaps," said Dmitry Gorenburg, a Russian military expert with CNA, a think tank. "They're going to be brought in as fresh bodies, primarily, to replenish the losses. … Folks who are suggesting they're bringing in everybody they can for one big push to break Ukrainian resistance. I don't see that as possible now."

Despite failing to score a quick victory, Putin is not relenting in the face of mounting international pressure. The Western world is aligned largely against Putin, but there have been no indications he is losing support from the majority of the Russian public that relies predominantly on state-controlled TV for information.

Ukrainian defenders, outgunned but benefiting from years of American and NATO training and an accelerating influx of foreign arms and moral support, are showing new signs of confidence as the invading force struggles to regroup.

Russian shortcomings in Ukraine might be the biggest shock of the war so far. After two decades of modernization and professionalization, Putin's forces have proved to be ill-prepared, poorly coordinated and surprisingly stoppable.

The extent of Russian troop losses is not known in detail, although NATO estimates that between 7,000 and 15,000 have died in the first four weeks — potentially as many as Russia lost in a decade of war in Afghanistan.

Robert Gates, the former CIA director and defense secretary, said Putin "has got to be stunningly disappointed" in his military.

"Here we are in Ukraine seeing conscripts not knowing why they're there, not being very well trained, and just huge problems with command and control, and incredibly lousy tactics," Gates said at a forum sponsored by The OSS Society, a group honoring the World War II-era intelligence agency known as the Office of Strategic Services.

Battlefield trends are difficult to reliably discern from the outside, but some Western officials say they see potentially significant shifts. Air Vice-Marshal Mick Smeath, London's defense attache in Washington, says British intelligence assesses that Ukrainian forces probably have retaken two towns west of Kyiv.

"It is likely that successful counterattacks by Ukraine will disrupt the ability of Russian forces to reorganize and resume their own offensive towards Kyiv," Smeath said in a brief statement.

Ukraine's navy said Thursday it sank a large Russian landing ship near the port city of Berdyansk.

Faced with such stout Ukrainian resistance, Russian forces have resorted to bombardment of urban areas but made little progress capturing the main prize of Kyiv. In an assessment published Thursday, the Atlantic Council said a major Russian breakthrough is highly unlikely.

Not long before Putin kicked off his war Feb. 24, some U.S. military officials believed he could capture Kyiv in short order — perhaps just a few days — and that he might break the Ukrainian military within a couple of weeks. Putin, too, might have expected a quick victory, given that he did not throw the bulk of his pre-staged forces, estimated at more than 150,000, into the fight in the opening days. Nor did his air force assert itself. He has made only limited use of electronic warfare and cyberattacks.

Putin is instead resorting to siege tactics against key Ukrainian cities, bombing from afar with his ground troops largely stagnant.

Stephen Biddle, a professor of international affairs at Columbia University, says Putin's shift is likely based on a hope that Ukrainian President Volodymyr Zelenskyy will give up rather than allow the killing and destruction to continue.

"This plan is very unlikely to work. Slaughtering innocent civilians and destroying their homes and communities is mostly just stiffening Ukrainian resistance and resolve," Biddle said.

Philip Breedlove, a retired Air Force general who served as the top NATO commander in Europe from 2013 to 2016 and is now a Europe specialist with the Middle East Institute, said Ukraine may not win the war outright, but the outcome will be determined by what Zelenskyy is willing to accept in a negotiated settlement.

"I think it's highly unlikely that Russia is going to be defeated in detail on the battlefield," Breedlove said, because Russia has a large reserve of forces. But Ukraine might see winning as forcing Russia to pay such a high price that it is willing to strike a deal.

"I think there is a chance of that," Breedlove said.

The Washington Post contributed to this report.