NATO was expanded anyway. With the threat of expanding NATO to Ukraine, Putin acted. I’m not saying invasion was justified but Russia has been clear on this point. They want a buffer. Either the west respects that or Russia will take territory to force it. So we are here we are today.
Anyway, no way Ukraine enters NATO. It’s also why Zelensky is trying prolong the conflict. He hopes to embroil one of the Actual NATO countries.