A recent report says North Korea may have the capability to mount a nuclear warhead on a missile.  However, the same report says that such technology is unreliable.

North Korean officials have been threatening an attack on both South Korea and the United States over February sanctions after a nuclear test and seasonal military drills by the South and the United States.

China, the North's only supporter, has not been happy with the totalitarian nation's raucous behavior.

There is belief that the North Koreans will test a missile on April 15th, which is the same day the Communist nation celebrate the birth of the 'eternal president' and grandfather of current leader, Kim Il-Sung.

One level of concern is the idea that North Korea would celebrate the occasion with a missile test.  And added concern is that missile going over Japan and the Japanese shooting it down.  After that, it is anyone's guess how the North Koreans would react.