I don't know anything about about taxation and foreign country business yields, but european companies obviously do business in the US as well, then there is TTIP etc. - there are more than enough possibilities for negotiations or pressure from the US.
Apple wrote a letter to their customers explaining their view on the situation
http://www.apple.com/ie/customer-letter/They argue that they do R&D in California and therefore should be taxed in the US. They also claim that the situation is the same for european companies in the US. Is the latter true (Kara, Puppy?)