Military might has plenty to do with bluffing. That's what politics is all about.
But when the music stops and the ball drops, US and EU aren't going to war with each other any time soon. So measuring military might doesn't really matter.
If Putin decides Poland is propping up Ukraine he might expand the war into Poland because right now it isn’t clear that the US would honor their NATO commitments.
Or it could just end with mutual total nuclear annihilation of course.
Edit: now if they were to attack the eu over a decades long interference campaign with its member state democracies, funding anti eu parties, stoking separatist sentiments, and covertly subverting the fundamental pillars of its liberal democracies, on the other hand…
Poland alone has a population comparable to Ukraine, and a significantly larger economy.
If EU countries commit to a conflict, Russia has no chance. It makes nuclear escalation a real risk though.