The Pentagon's new national defense strategy calls on the Army, Navy, Air Force and Marines to boost investments in irregular warfare capabilities by assuming "greater risk" in traditional combat capability areas, a controversial conclusion that Defense Secretary Robert Gates endorsed last month over the objections of top Pentagon brass. "U.S. predominance in traditional warfare is not unchallenged, but is sustainable for the medium term given current trends," states the 2008 National Defense Strategy, a copy of which was obtained by...