Mortality statistics suggest that nearly a quarter of all men who have a stroke after the age of 65 -- Kim will turn 68 on Feb. 16 -- will die within a year. The odds of surviving five years are about 50-50. For diabetics -- and Kim is believed to be one -- a 2008 Indiana University study reports that life expectancy is 15% lower. So, although his prognosis is not terrible, neither is it very good.
Why should we care? As a nuclear weapons state and exporter of ballistic missiles, North Korea has long been a proliferation headache for Washington. With one of the world's largest armies in possession of long-range artillery and rockets, it also can wreak havoc on South Korea and Japan -- America's most important Asian allies. And with neighboring China and Russia also engaged in the Korean peninsula, there are few other places where the interests of so many great powers intersect and potentially collide. So who governs North Korea is not a trivial concern.
Were Kim to die suddenly or decide to relinquish power, one of his three sons could take over, as Kim did from his father. But given their young age or inexperience, a collective leadership made up of senior officials with perhaps one of the sons as a figurehead to promote regime legitimacy is widely considered more likely. It is by no means certain, however, that this would work or last very long.
Certain individuals or factions -- not least from the army or intelligence services -- might be tempted to seize power, resulting in a potentially disruptive and even violent leadership struggle that could put immense strain on the rest of the country. Totalitarian states have proved to be remarkably brittle when stressed by internal pressures, and North Korea may be no exception.
Should North Korea begin to collapse, the world could face a host of challenges, including huge outflows of refugees, military provocations, a breakdown in public order and, most ominous, uncertainties about the safety and security of its nuclear arsenal.
All this would inevitably put pressure on neighboring states to intervene to stabilize the situation. Given their competing interests, the potential for misunderstanding and conflict because of unilateral or uncoordinated actions is considerable.
For these reasons, the new U.S. administration must enhance its preparedness to manage destabilizing change in North Korea.
First, it must improve its capacity to better understand developments in North Korea while overhauling U.S. contingency plans to ensure a comprehensive and coordinated government-wide response. This should draw on the lessons from ongoing operations in Afghanistan and Iraq, among other places.
The United States also should work closely with South Korea and Japan to improve allied coordination and preparedness. Planning to date has been rudimentary and stymied by political differences between Seoul and Washington. In particular, the military preparations need to be undergirded by an integrated political, diplomatic, economic and legal strategy. Tokyo must be brought into this process.
Finally, the U.S. should pursue a quiet dialogue with China to reduce the risk of misunderstanding and friction in a crisis involving North Korea. The aim would be to anticipate potential concerns and provide mutual reassurance of each country's intentions.
How long Kim stays in power is anyone's guess, but the risks are too great and the stakes too high to rely on last-minute improvisation for the day after.
Paul B. Stares is a senior fellow at the Council on Foreign Relations and the coauthor, with Joel S. Wit, of "Preparing for Sudden Change in North Korea."