North Koreans have formally ended their three-year mourning period for Kim Jong-il. By custom his son, Kim Jong-un, and the country now are free to move forward without hindrance from the past. But no one knows how they will take advantage of their opportunity.

A small, poor nation, the Democratic People’s Republic of Korea should be an international nullity, irrelevant to global affairs. Yet it again dominated headlines in the U.S. with the hacking of Sony and cancellation of the broad release of the movie The Interview, a comedy featuring the assassination of the younger Kim.