The wests fear that Putin might use nukes has kept them out of Ukraine (not because Ukraine isnt a NATO member).
If Putin stays in Power, he will eventually move on the Baltics, and Article Five will be shown to not be worth the paper its printed on.
Based on his incompetence that has been exposed
The missile my fly straight up and come down on his head
Putin used NATO as an excuse to act like Psycho Hitler. Now that Ukraine says NO to NATO, Putin changes his "red line" for the zillionth time. Oooohhhhhh, we are so scared of your saber rattling you little, little, LITTLE eunuch. He doesn't have a Napoleon Complex, he is just plain psycho on power and $$$$ (like his little/huge girlfriend, tRump).
As long as he keeps pushing without any repercussions, he will continue.
no better reason than when we let Hitler gain power. We are simply afraid to go through the hell of stopping him. And that hell is actually a serious problem, with nukes. Even if most Russian nukes don't work, the few that do will destroy anything good on the planet.
This must end with the destruction of Putin as an example of what happens to powermad lunatics.
Not to be flippant but as Barney Fife used to say nip it nip in the bud. Poo Poo Butt is like cancer. Stop it in its tracks else it spreads everywhere.
Ukraine is holding with the aide of NATO support as well as the support of virtually the rest of the world. Russia doesn't have the conventional strength to take this outside of Ukraine, much less tangling with NATO.