Econimic boost? Americans are under themselves only. They have own schools, shopping centres, bowling, disco, bars and what else in the bases. They don't buy in german stores. They only drive around playing big.
When I was at friends, a big Jeep with american licence tried to push me off the street, because I drove 120km/h instead the allowed 100. I was too slow for that asshole. At a parking lot he(in uniform) screamed really bad things. It was good, we were four in my car(have tinted window, so he couldn't see). The guy was fast back in his car, when my friends got out of my car.
There is no reason for them to stay in other countries, playing big boss and world leader.
I don't like the way, americans act in the world, as if they can do everything and all the others has to follow their will. And if someone critizizes, they bomb them out or call them terrorists friends.