Well under Arsene Wenger, Arsenal have basically become a French team playing outside the French League. Apart from Sol Campbell they havent really done the England team any favours.
Similarly, Liverpool under Rafa Benitez is on the verge of becoming a spanish team (I quite like spanish football), and I guess apart from Steven Gerrard, you wont have too many englishmen in that squad.
But atleast by signing players like SWP, we are giving him a chance to play Champions League Football, and hence get used to playing with the big boys of Europe. This can only benefit England. Lampard and Terry, two of the finest players in the world, became stars at Stamford Bridge. Wayne Bridge who used to play for Southampton, became a better player after playing in the Champions League.