Increased demand helps explain why shares of U.S. contractors including Northrop Grumman (NYSE: NOC), Lockheed Martin (NYSE: LMT), Raytheon (NYSE: RTN), and General Dynamics (NYSE: GD) have all more than doubled over the last five years, and suggests that even after that surge more gains are possible. In particular Lockheed Martin and Raytheon, both strong on missile-defense, figure to be big winners in Europe.