JUST over three weeks after the Americans dropped “Little Boy” on Hiroshima, General Douglas MacArthur took off from Okinawa into another clear blue sky. To Courtney Whitney, his pompous if devoted aide (described by detractors as “a stuffed pig with a moustache”), the new American proconsul dictated a few staccato thoughts on what he would do with Japan:

“First destroy the military power…Then build the structure of representative government…Enfranchise the women…Free the political prisoners…Liberate the farmers…Establish a free labour movement…Encourage a free economy…Abolish police oppression…Develop a free and responsible press…Decentralise the political power.”

MacArthur then took a nap. When he woke, the plane was already on its descent to Atsugi air base just outside Tokyo.

If only someone had a plan like MacArthur's for North Korea. This week the country celebrates the 68th birthday of Kim Jong Il, or perhaps his 69th: the exact year of the birth miracle on the holy slopes of Mount Paektu is unclear. Mr Kim has built on his father's efforts to foster a totalitarian military state founded on the idea of racial purity and put to the service of a quasi-divine family. The model has a strong Confucian flavour, and also a feudal one, where a knightly band of brothers swears fealty to its king. But the chief inspiration is racist, militarist, imperial Japan of the 1930s. This is the grim tragedy for a land oppressed by Japan for half a century.

Even without invading others as Japan did, the North Korean regime will crumble, perhaps soon after the immortal Mr Kim's number is up or possibly even before: reports of popular protests sparked by a hugely ill-judged currency confiscation may be a harbinger. Thoughts ought to be turning to North Korea after Mr Kim.

Yet as Sung-Yoon Lee points out in Foreign Policyhere (the picture desk has a sense of humour), precious little thinking about it has been done by the United States or North Korea's neighbours. At best, contingency plans exist for dealing with the short-term emergency generated by a collapse of power in Pyongyang. Even Chinese policymakers accept that American special forces might, or even should, move in rapidly to secure nuclear, biological and chemical stockpiles from rogue groups within the military. Chinese troops, in turn, would probably move across North Korea's northern land borders to enforce the peace there. The Japanese navy would bring in supplies to the coast and pick up refugees in leaky boats. A massive humanitarian effort, led by the South Korean military, would get under way.

But beyond that, nothing much. In interviews with South Korean, American and Japanese officials, I have often been amazed at the lack of long-term thinking about North Korea: out of sight, out of mind. But one thing I am pretty sure about in all the talk of eventual unification is that it will not, by any stretch, be unification, German-style. Far from urging North Koreans to come across the border, it is easy to imagine South Korean and American troops enforcing the 38th parallel to keep a wave of North Korean refugees from heading south into a well-fed land. And if they keep on coming, what should the soldiers do? Shoot? The desire to keep North Koreans in their miserable cantonment may prove a real test of liberal values.

The one exception to the lack of long-term thinking may be China. Its commercial interests in North Korea are only growing, as it eyes mineral rights and access to ports on the Sea of Japan. China's political imperative is for a stable North Korea. Andrei Lankov, a perceptive watcher of North Korea at Kookmin University in Seoul, raises the possibility of China attempting to avert collapse by installing a hard authoritarian, pro-growth regime in North Korea, something along the lines of China's. Perhaps a third-generation Kim might even be made the impotent figurehead, like Emperor Hirohito after the war, but the power would lie elsewhere.

A Chinese game plan like this would shock the region, humiliate the United States and upset all sorts of regional strategic calculations. But North Korea would have found its MacArthur, admittedly with Chinese characteristics.