It started way back when the USSR had fallen apart and NATO (at Clintons behest) having assured Russia it wouldnt expand closer to its borders, did the complete opposite and took advantage of Russian weakness, by starting to expand eastwards.
This created the siege mentality in Russia that allowed Putin to come to power.
If they had treated Russia the way they treated Germany after WW2 things may well have been very different.
Then in 2014 the EU (probably egged on by the U.S.) covertly helped organise the overthrow of Ukraines "Russia friendly" President which reinforced Putins message to the Russians that the West was out to destroy Russia and he was the man to save them from this.
Stupid western leaders - Clinton, Obama, and the EU lot, stumbled into this.
His invasion of Ukraine though has, so far, bit him on the arse. Ukraine have put up a hell of a fight, which he didnt expect, and his actions have brought some unity and purpose to the previously divided and complacent West.
NATO now has good justification to expand right up to Russia,s borders and will almost certainly do so.
As a strategist the man is an idiot.
Two possible scenarios left to play out imo. Someone in Russia does something about him, or he takes the world to the brink (maybe beyond it) of WW3.
As the irritating tit Sting once sang "I hope the Russians love their children too".