Washington has been beefing up its joint exercises with South Korea and has added flights of its nuclear capable air craft near the Korean Peninsula, first B-52 bombers and now the B-2 stealth planes.

WSJ: U.S. Flies Stealth Bombers Over South Korea

The case for putting anti-missile defenses into place was underscored by this sobering fact: A ship like the North Korean vessel that was covertly carrying Scud B missiles and forcibly intercepted in the Arabian Sea last week could be steaming off the coast of the United States at this very moment.

CENTERFORSECURITYPOLICY: Serious about defending America

It followed similar missions earlier this month by B-52 bombers during the annual U.S.-South Korean war games.

WSJ: North Korea Warned

On Thursday, the North Korean army issued a statement threatening US military bases in Japan, in response to the US flying nuclear-capable B-52 bombers over South Korea as part of a joint military exercise.

BBC: UN to investigate North Korea human rights abuses