Ukraine

Eh, Putin is primarily interested in taking over old USSR territory and restoring Russia to their former power. Even he isn't dumb enough to intentionally fire a bullet at a NATO member, as it would not go well in his favor. Sure, they have nukes, but a lot has changed in the last ~40 years. It isn't even certain his nukes could hit many of their critical targets before being shot down or have their guidance systems meddled with. I'm not sure he could even really rely on China backing him up, as they wouldn't see much value in going head to head with NATO. They're much more inclined towards the long term strategy that's been working quite well for them so far.

With that being said, I hope I'm not proven wrong. War is horrific and I truly wish for me and my offspring to never see the day another world war breaks out.