The concern is that when a strongman is in power and backed into a corner, they have very few ways out of that corner. Their systems are designed in ways to suppress the possibility that someone will try to coup them, and to keep the population from getting too unstable.

One of the more reliable ways to keep the ball rolling is to keep the situation so ugly and chaotic that its too costly for anyone to want to come in and replace them.

It looks like madness to us, but when you look at it through the lens of self preservation atop a fundamentally corrupt system lacking in checks and balances, it starts to make a sort of twisted sense.

At the end of the day, Russia is more or less immune to ground invasion, due to the nuclear threat. So, there isn't a whole lot of reason not to broaden the conflict, just to buy a couple more years of personal safety for the guy on top.

One rational way to attempt to head that off is to power up to the degree that a ground invasion would rapidly fail, not buying a couple years, but instead just hastening the decline through more military catastrophes. So, free people may consider mobilization, to posture strength and scare off aggression. Posture strength and sabre rattle, so you don't have to fight a war.

Or, y'know, we could just arm Ukraine and let them do the job. But Putin is undermining that effort with every resource at his disposal already.

It's unlikely to be WW3 at any rate, because Xi Jinping would want no part of such a dangerous and short-sighted undertaking. Though, he could use the distraction to try to take Taiwan.