The North Korean leader's 27-year-old son is next in line, but the military might not support him



Kim Jong Il, far right, and son Kim Jong Un, second from left, salute a military parade in September / Reuters

Kim Jong Il probably knew he didn't have much time left when, 15 months ago, he held the first "Worker's Party Conference" -- a gathering of North Korea's political and military leaders -- in 30 years. There, he established his successor: Kim Jong Un, his heavy-set, Swiss-educated, and reportedly not very bright son, then 26 years old. Sure enough, North Korean state media, almost immediately after it announced Kim Jong Il's death, declared Kim Jong Un as the new leader.

Since September 2010's big conference, the state machinery has been turning constantly, and often noisily, in preparation for this day. There have been changes in official state history, cabinets have been reshuffled, an unprovoked shelling of a South Korean town likely meant to rally soldiers and civilians around the flag, and an endless output of Stalinist-style propaganda. Today, that machinery seems to have functioned well, as it often did under Kim Jong Il. But the question now is who will really run it and to what purpose.

The greatest threat Kim Jong Il poses in death, just as in life, is not that his state will commit an act of unprovoked aggression, but that it will collapse. Though he likely spent much of his final year preparing for his son's smooth take-over, it may not have been enough time. What little we know of North Korea's leadership suggests that a regime under young Kim Jong Un could invite challenges from the military or even from his own political circle. We don't know for sure if Kim Jong Un has as much power as his father, but either way there is reason to worry about the state's stability under his rule. If he really is in complete control, the reports on his intelligence suggest he will stumble, at which points military leaders worried about the country's stability may be tempted to intervene. If, however, his power is less total, then that will invite jockeying between political and military leaders for influence, something that North Korea's tightly regimented political system was never made to account for.