I believe that the expansionist policies of NATO and the EU gave Putin the excuse to do what he did, but now he has done it he must be stopped regardless that.
It was the EU and their Association Agreement which kicked it all off much more than NATO, as Putin didn't want Ukraine becoming an EU satellite.
There was never any prospect of Ukraine joining NATO, although if they had joined maybe this mess wouldn't be happening.
Wrong. Putin said he would accept Ukraine in the EU as it's not a military bloc (well not at the moment anyway).
https://www.euronews.com/2022/06/18/uk-ukraine-crisis-eu-russia
That article is from 2022, Putin's attitude was very different in 2013 when he pressured Viktor Yanukovych the then Ukrainian President to abandon the EU Association Agreement that had taken years to negotiate literally days before he was due to sign it, in favour of a trade agreement and loan guarantees with Russia.
We all know what happened next... EuroMaidan, Yanukovych's downfall and Russian exile, Russia's
Little Green Men invasion of Crimea and the start of the Ukraine/Russia war in the Donbass.
Some say that the downfall of Viktor Yanukovych was a coup organised by the CIA!
Now I love a good conspiracy theory, but given the well documented events of the time, I think it's more likely that the moon is made of Swiss cheese and that the Clangers do indeed live there.