Should their first move be an invasion of Russia?
what no
I'd prefer if we didn't have another world war.
Besides, isn't this what NATO is for? Shouldn't the EU be more concerned with economy?
It would be suicide anyway. To make up for their perpetually lackluster military pro-USSR, Russia has made it clear that they will use nuclear weapons if met with overwhelming conventional forces. I would think a large military group blowing past their border would count 
This.
We're not in Napoleon's day anymore where you could just say "f*** it" and invade the next country without massive damage worldwide.
Global economic interdependence, basically. We need Russian gas, they need our money.
