[avmich]

Should we admit that world wars don't need to involve superpowers - or at least only superpowers? The term wasn't that much applicable before end of WWII.

So here we can argue that in WWIV a non-superpower fights - Ukraine, on its territory, a superpower - USA, merely - but with principal results - supporting Ukraine, and the rest of the West. We may not call it a proxy war - I agree, it's a rather poor comparison - but for WWIV term it is another matter.

[trasz]

World wars don't need to involve superpowers, but they need to involve large part of the world. Russian invasion on Ukraine doesn't, and it's unlikely to escalate - Russia can't, because they have neither people, hardware, or allies, and the defending countries don't have a reason to.