The death of Kim Jong-il was always likely to be an unusually dangerous moment for what Kevin Rudd, the Australian foreign minister, described yesterday as “the single largest militarily armed zone in the world”. But it has also happened at a moment when the US and China are perilously far apart on how to deal with the isolated Stalinist nation.

Leaked US diplomatic cables last year gave the impression that the ground was being prepared for a grand accommodation between China and the US over the future of the Korean peninsula. One of them quoted a Chinese official saying that North Korea “now had little value to China as a buffer state”.

The reality, however, is very different. Chinese support for North Korea is probably one of the most controversial aspects of the country’s foreign policy.