From what I can tell, you merely skimmed my post before deciding to go off on your rant, which certainly taught me a bunch of details I didn't know, but contained very little to actually dispute my basic point.
Russia's strategic interest in keeping Ukraine outside of NATO, their discomfort with other Eastern European nations having already joined NATO, and their emotional connection to the Russian speakers in Ukraine or the Baltics whose linguistic and cultural rights aren't sufficiently respected, are all valid points. Which is why, throughout most of this crisis, Putin had not only broad support inside Russia, but also a fair bit of understanding or more explicit support outside it, even when he took the legally questionable step of recognizing the Donetsk and Luhansk republics.
But when he went on his ludicrous rant about Ukraine and then actually invaded it, not just bolstering the separatists in the east but a massive multi-pronged invasion focused on Kyiv, it became an entirely different story. Which, as I wrote in my previous post, left his supporters, domestic and especially international, with an awkward dilemma - in which I see you've chosen the 'double down on the insanity' option.
The decision to actually declare war on this scale, as opposed to what he's been doing for the past twenty years which in case you didn't notice was often quite successful, was definitely one person's fault - or perhaps one person and a handful of his closest advisers. By all accounts, there's precious few people left in the Kremlin who actually influence Putin's decisions.
You know what WAS put on paper? Russia's commitment to Ukraine's existence and territorial integrity - and, much later, to the Minsk agreements on how to resolve Ukraine's problems in the eastern provinces. Why did NATO expand eastward? Because the countries in question were afraid of Russia trying to conquer them, obviously. Which Putin has just proved them right on - he just tried telling Sweden and Finland not to join NATO, because even in his insanity, he realizes that his actions just now have ensured that every remaining neighbour of Russia who isn't already in NATO will now be desperate to join it, even if they weren't before.
So do you actually expect anyone to believe that Russia figures Joe Biden, or any other American president, will try to become the next Napoleon and attempt to conquer Russia? Poland, the Baltics, the Caucasian and Central Asian republics, they've all been invaded and occupied BY Russia and if some of them want to join / have joined NATO, it's to be defended from Russia. Same goes for Ukraine although obviously that's a more complicated story with different parts of Ukraine having different degrees of historical affinity to Russia.
Do you realize how ridiculous and childish you sound? As the saying goes, a language is a dialect with an army - with this kind of reasoning, Haiti should remain a French colony in perpetuity because Haitian creole is essentially simplified French, or the same with Afrikaans and Dutch. And while we're at it, we could start about how English is basically a bastardized, Frenchified version of a Germanic language so we should just hand the US and UK back to Germany for proper language training.
Funnily enough, Russia wants all the credit for the achievements of the Soviet Union, as well as its great power perks like the Security Council seat and the nukes, yet none of the blame for its crimes. Though of course that kind of selective memory is a pretty universal sentiment among nationalists in any country and I've no doubt the Ukrainian nationalists are just as bad.
The shocked reactions from the Russian public and both Russian and foreign Kremlin analysts tell a very different story re: 'any other Russian government acting in a similar fashion'. His steps in the preceding weeks, yes, as I acknowledged above. This war, fuck no.
Well, going by some of what you wrote here, you seem to share some of his demented hatred of all things Ukrainian - but from what I can see, most Russians take a more reasonable view of the situation. And most Russians can see what apparently Putin and you can't: that this war will only leave Ukraine more antagonized, Russia more isolated and poorer, and the legitimate strategic goals of the Russian government further removed than before.