Now we have a capabilities-based system and, after six years, I still don't know what that means—even after spending part of that time in the Pentagon! And while we call it capabilities-based, I'm not sure there is a readily understandable explanation of just what process determines just what capabilities are required. Even without a superpower bogeyman, it seems that the current assessment is that bigger—and more capable—is better.
Colonel Brilakis' full article (recommended):
Martian Alert!
by Colonel Mark A. Brilakis, U.S. Marine Corps, Proceedings, January 2006