Putin will have no choice in this case. Ukraine will be aligned with NATO whether he likes it or not. Ukraine has decided to align with the West, and there is no turning back after this war. Putin lost Ukraine for good. What will be decided is just where the borders between Ukraine and Russia will be.
Sooner or later Ukraine will be in the EU and in NATO. It is just a question of time. It will take many years, probabaly a few decades, but it will happen. Russia will not be able to stop it, because this is what Ukrainians want.
Putin will have
every choice in this case. Trump wants the war over, he's not big on NATO in the first place, and Ukraine's in a weaker negotiating position by the day.
Putin's morally in the wrong here, but his position hasn't changed. "Stop flirting with my border, you wouldn't tolerate me fermenting anti-Washington political movements in Canada and/or Mexico. Fuck off, Obama." Is what it was then. That's the same deal now. Of course Ukraine's never being
Russia-aligned again, that goes without saying, but they
will be the buffer zone between NATO and Russia that they have been since 91. Because the alternative is...this, and the west isn't willing to go further and escalate more than this over Ukraine, a country none of them cared about pre-2021. Ukraine's free to fight as best they can, war to the last Ukrainian, but that's it, that's the ceiling.
Putin's aware, and he can absolutely play the "remaining part of Ukraine stays Ukrainian, we don't advance further, America/European Union quits meddling in-country" card. It'll work, because A) we're pussies, and B) we don't care about Ukraine to half the extent we say we do, push comes to shove. When it's easy and it's just cash in an account and throwing Zelensky our hand-me-down kit, it's fine. End of the day though, Russia's still winning on the ground here, and there's no "kick this up a gear militarily" from our perspective so long as it's just Ukraine and not Poland. Putin goes further, he's having a bad day, but he won't, because he can't. He
can beat Ukraine into submission as far as ceding the Donbass & Crimea and signing away NATO entry though, and ultimately that's what'll happen.