WASHINGTON — North Korea faces the danger of an unguided missile strike, aimed right at the center of power from a direction both near and far.

That would be the newly installed supreme leader’s elder half-brother, Kim Jong Nam, who has made some skeptical comments about the weakness of the bloodline that show an unusual insight into what’s going on in Pyongyang even though he’s a few thousand miles away.

The wires are abuzz with news of a soon-to-be-released book based on emails and interviews between Kim Jong Nam and a Japanese journalist Yoji Gomi over a seven year period. In the book, which is called “My father Kim Jong Il and Me,” Jong Nam reportedly said that North Korea is bound for collapse and called his half-brother, Kim Jong Un, a figurehead.

What “a joke to the outside world,” Jong Nam is purported to have said of the ascent of Jong Un, whom he admitted he has never actually met. More seriously, Jong Nam predicted, “The Kim Jong Un regime will not last long” and “without reform … the regime will collapse.”

The ruling elite in Pyongyang, the ones who are really in control, must be wondering what to do about a problem like Kim Jong Nam, a man who is, it seems, unafraid to speak his mind from where he lives in China....