You, like many other commentators, intentionally or not, keep pushing NATO expansion as a threat to Russia. It is not now, nor has it ever been a threat, and Russia knows this. NATO is a purely defensive alliance, whose members are admitted because they ask to join. Before Putin took control of Russia as its president in 1999, there was even discussion about Russia joining NATO. The increase in NATO membership in recent years by former countries dominated by the old Soviet Union is a reflection of the fact that they fear future Russian aggression.
Their fears are well founded. Putin has made it clear that the greatest disaster to ever befall Russia was the dissolution of the old Soviet empire. He has deluded visions of grandeur of reestablishing a great empire that never was. His annexation of Crimea was part of this. It was not a response to a threat by NATO. You’re pushing a common fiction, which has absolutely no basis in fact.
When Putin started the war, he made no mention of NATO. His reasons included denazifying Ukraine, the fact that Ukraine was not a real country, and protecting Russian speakers who were under attack by Ukraine in the eastern oblasts. All of these were lies, and he no longer embraces them. Indeed, because NATO took no action when he annexed Crimea, he viewed them as weak, and that they would do nothing to stop his invasion of Ukraine. He was wrong. His excuse now is that he is caught in an existential battle with NATO because NATO wants to destroy Russia. NATO has no such interest or intent. All its members just wish that Russia would withdraw to its own borders and end this war. It’s up to Putin. But of course he is not reasonable and would never do that.