Who'd you think win between both of them?
I'd take for the EU as they have already a great common share in common security with over 1,551,038 active personel in 2012 and 546 ships, 2,448 aircraft & 7,695 battle tanks, I couldn't imagine if they throwed in all of their military power and budget. The budget at a 1,55 percent GDP base on the military is over 192 Billion euros. This debate includes only conventional weapons. And plus, the ennemies of the US would take pleasure in joining the war. (china, north korea, russia, etc.)