Kang Myong Do, 36, the son-in-law of Kang Song San, the Prime Minister of North Korea, sowed the seeds for a real-life John Le Carre mystery among intelligence agencies in Seoul yesterday, with his claim that North Korea's nuclear weapons' programme has gone further than the worst fears of the West.
North Korea is due to reopen high-level talks with the US in Geneva next week over its nuclear programme, which it claims is for civilian use. The US is optimistic about the chances of success, but warns it will not hesitate to turn to United Nations-sponsored sanctions, if the North Koreans revert to their old prevaricating strategy.
Washington is encouraged by the fact that Pyongyang has agreed to restart the nuclear talks so quickly after their suspension, following Kim Il Sung's death three weeks ago. It is also cheered by signals in the state media that it will be willing to give in to demands for full-scale nuclear inspections in exchange for economic aid.
But the claims by Mr Kang have confused the Americans. Mr Kang said that after making five nuclear warheads, North Korea is working on missiles that could deliver the devices over long distances. 'North Korea is not simply trying to use its nuclear development programme as a negotiating card,' he said in Seoul yesterday. 'It sees nuclear development as the only means to maintain Kim Jong Il's regime.'
Up to now, the worst-case scenario of the CIA has been that North Korea was able to make one or, at most, two primitive nuclear bombs. This is based on a mysterious shutdown of the nuclear reactor in Yongbyon, north of Pyongyang, for 100 days in 1989, during which the CIA estimates that enough plutonium could have been extracted from irradiated fuel rods in the reactor core to make two small devices. If it is true that North Korea has five devices, an urgent question is where the extra plutonium came from.
It is not clear Mr Kang is telling the truth. According to Seoul, he defected via a third country in May, giving South Korean intelligence agents two months to debrief him and, conceivably, prime him with whatever propaganda story they wanted. Alternatively, Mr Kang's defection may have been planned by North Korea to give the impression that its nuclear programme is more advanced than it is, thus increasing its bargaining power.