What is the threat of a 'cornered' Putin as the Russia-Ukraine conflict drags on?

Long before the first shot was fired, diplomats the world over have been trying to find a way to broker some sort of peace between Ukraine and Russia.

After two grueling weeks of bitter combat, that goal is more elusive than ever.

With the war seemingly poised to drag on, ABC News spoke to foreign policy experts about Russian President Vladimir Putin's next strategic steps, the fine line the West is walking to support Ukraine, and how the conflict could ripple beyond its borders.

'A cornered beast, if you will, can be dangerous'

Putin's invasion into Ukraine has been met by expectedly punishing sanctions from the U.S. and its allies, as well as unexpectedly effective resistance from Ukrainian fighters. At least for now, both seem unlikely to change the Kremlin's calculations or diminish Putin's determination.

While it will take time for Russia to feel the full impact of economic restrictions levied against it and Ukraine's ability to withstand a prolonged assault is an open question, Dan Hamilton, a former high-level State Department official and now a senior fellow at the Brookings Institution, said pushing Putin to the brink could have unpredictable consequences.

"In his mind, he doesn't want to go down in history as the leader who 'lost Ukraine,'" he said. "A cornered beast, if you will, can be dangerous."

But despite setbacks, Andrew Lohsen, a Russia expert at the Center for Strategic and International Studies, says Putin is undaunted.

"We've heard from Vladimir Putin himself that he thinks that this war is still winnable. He hasn't given up on his objectives. And his he seems still very determined to press on," said Lohsen. "The indications that we have so far is that he is still really doubling down and pressing further with his invasion rather than taking a step back."

Just as they made clear what the consequences of an incursion would be before Russia advanced into Ukraine, Lohsen says world leaders will ultimately need to identify an "off-ramp" for Putin by indicating exactly how de-escalation will yield sanctions relief.

"We need to give the sanctions time to bite," he said. "Once we start to see some sort of concern among the top levels of leadership, then I think it would be appropriate to start a conversation about the conditionality of these sanctions. What would we remove in exchange for a withdrawal of Russian forces?"

But whether Putin will elect to take that off-ramp is another question entirely.

"My concern is that Putin has painted this conflict in such hyperbolic terms, I think it's going to be really hard for him to step back from the brink. He said that Ukrainians have committed genocide, he said Ukraine has a desire to acquire nuclear weapons," Lohsen said, referencing the lies Putin used to justify military action. "So when you're engaging in a war with a state with such supposedly nefarious aims, them how do you reach a negotiated solution where you leave that leadership in place and you don't completely stop that country from pressing on with the objectives you've ascribed to it?"

And for Putin, negotiating an end to the conflict he started wouldn't mean an end to its consequences.

"They want to bring Putin up on was crimes -- take him to The Hague. Those things don't go away," said Hamilton. "It's very hard to see how Putin would sign an agreement when he's being prosecuted."

Should the US and allies do more?

Amid an onslaught of grim reports and haunting images from the streets of Ukraine, a "wait and see" kind of approach can feel frustratingly futile. While the crisis has prompted a rare bipartisan outpouring of support in the U.S., funneling assistance to the country remains a delicate dance.

Ukraine's President Volodymyr Zelenskyy has repeatedly called for establishing a no-fly zone over Ukraine to protect civilians, but the Biden administration and NATO have made it clear it's a nonstarter because enforcing airspace restrictions would almost certainly mean direct conflict with Russia.

"The fear of nuclear escalation is the number one consideration here," said Clint Reach, a former Russian linguist with the Department of Defense and a policy analyst at RAND. "That's the elephant in the room when it comes to direct military intervention."

As made evident by the Pentagon rejecting Poland's plan to send fighter jets to Ukraine via a U.S.-NATO airbase in Germany, there's significant concern that roundabout assistance could also spur significant blowback.

"We don't have a full understanding of Russian red lines and how much intervention they're willing to accept," said Reach.

Zelenskyy and Republicans on Capitol Hill have argued that funneling more military equipment into Ukraine sooner would have made a difference in the conflict. Experts aren't so certain.

"We could have just sped up the invasion timeline," countered Reach. "No Russian president is ever going to allow Ukraine to become a U.S. aircraft carrier—meaning Ukraine becomes a platform for military capability that could threaten Russia. If they felt that scenario was playing out, they probably would have intervened."

"Until Russia began its invasion of Ukraine, I think there was adequate caution in trying not to engage in anything that might provoke this scenario," said Lohsen. "What we got wrong collectively was the belief that Putin could be deterred."

Could the conflict spiral beyond Ukraine?

Despite the great pains taken to avoid escalation, many predict it's only a matter of time before the discord metastasizes further into Europe -- and perhaps even beyond the continent.

Hamilton points out that while Moldova -- a small country abutting Ukraine's southern border -- has already seen a surge of refugees fleeing the fighting, it could also become a launching pad for Russian troops closing in on Odesa.

"Moldova is one of the poorest countries in Europe," Hamilton said. "We already have a humanitarian crisis, and we could have a next crisis of military escalation involving troops coming not just from Belarus and Russia, but also from Moldova. That's very problematic."

And while Western powers attempt to walk a tightrope while supplying aid to Ukraine, whether they are ultimately drawn into the fight depends in part on Russia's reaction.

"The question has been would Russia try to preempt some arm transfers at the point of origin—like firing missiles into Poland at bases where they thought this military equipment was housed," said Reach, noting that while that would be at the severe end of the spectrum, the Kremlin could also retaliate with asymmetric attacks, like cyberstrikes.

While escalatory, Reach believes it's a move Moscow could ultimately make.

"There are potentially large tradeoffs for Russia that they'd have to think long and hard about," he said.