Yeah, answer is geopolitics. Germany is main country that wants united EU. UK+US don't want that, because united EU is big threat. Think what could happen if EU

Yeah, answer is geopolitics. Germany is main country that wants united EU. UK+US don't want that, because united EU is big threat. Think what could happen if EU start connecting more on euroasia (Russia, China, India). From American point of view it would be fatal (one big territory they can't control), but for the rest of the world it would be, well, good. So, Americans are playing double game: be good with allies and keep them weak (remember Greece?).