Depends on lots of things. Most importantly who is attacking who?
If it is ANYONE else attacking the United States then i is a win for North America. If it is North America attacking the continental Europe then it would be a much closer battle. The United states spends FAR MORE on military prowess than any other nation behind by a HUGE margin. The united states wins a battle on its home soil because of one simple factor. PROJECTION. No other country on earth has the transports necessary to bring their personall across the oceans to attack the US. Especially without the Worlds mos powerful navy knowing about it. America also has by far the most powerful air force which would be able to destroy all incoming aircraft and missiles.
Hence a defensive battle is a win for North America. No contest. As for attacking the US does have sufficient ability to deploy troops anywhere in the World and enjoys a technical advantage over any other military in the world. Given these facts I think THe US would eventually lose if they were to invade European Soil but they would get hell of a lot farther than Europe would get on the US
Long Live SHIO!
