It’s not about Nato. It was never about Nato. There are Nato countries on Russia’s border already and that didn’t seem to bother Putin. The reason for his invasion is in a long rambling ‘manifesto’ he wrote and posted to the Kremlin website last year. It’s still out there. Basically Ukraine doesn’t exist. No such country as Ukraine. It’s all Russia. Ukrainians are Russians. Putin simply taking back what belongs to Russia.
It is either stop Russia in Ukraine now or wish we paid the price for it later. Putin made his choice to not allow any other choices.
Putin’s obsession with Ukraine is existential. Kiev Rus are the true Russians culturally and historically. The last leader of historical Russia was executed by the Bolsheviks in Yekaterinburg in 1918. The current ‘Russian’ leadership is the descendent of the Bolshevik criminal gang that destroyed Russia in the civil war following the murder of its Czar.
This is why Putin is obsessed with Kiev. He knows his country, his progeny and his claims to Russia are moral, ethical and historical frauds.