A great power without a significant enemy? That's what the U.S. has become.

Osama bin Laden is dead. Al Qaeda is reportedly a shadow of its former self. The great regional threats of the moment, North Korea and Iran, are regimes held together by baling wire and the suffering of their populaces. The only incipient great power rival on the planet, China, has just launched its first aircraft carrier, a refurbished Ukrainian throwaway from the 1990s on whose deck the country has no planes capable of landing.