The denuclearisation deal hammered out with North Korea is unsatisfactory. It is nowhere near as comprehensive and unequivocal as the resolution that was passed by the UN Security Council last October in response to Pyongyang’s nuclear test. It omits any reference to North Korea’s biological and chemical weapons programmes, and defers to a later stage such critical questions as Pyongyang’s suspected enrichment of uranium. It is expensive: $300 million of oil — equivalent to around two thirds of North Korea’s annual oil consumption — looks suspiciously like rewarding bad behavior. Pyongyang’s undertakings will be inordinately difficult to monitor, and not only because it has broken all previous promises. The country is pocked with tunnels, bunkers and subterranean chambers where production facilities could be hidden.

Above all, this agreement comes late in the day. That is not the fault of America, which has tried much harder than its critics concede to keep the lines open. To do that, it had perforce to rely on China, the only state capable of bringing North Korea back into line. Yesterday’s start down the road to denuclearisation could have begun long ago, well before Pyongyang was able to test a nuclear device. The problem was that Beijing refused to lower the boom earlier, using its connections with disaffected pragmatists within the ruling clique while also curbing the flow of oil, grain and luxury goods that prop up Kim Jong Il’s bankrupt regime. China did not want the nuclearisation of the Korean Peninsula, but mistakenly believed that Pyongyang would not defy its only protector by going nuclear.

This deal stands a chance only if China is serious. Despite its limitations, it is an important first step. The original agreement reached with President Clinton in 1994 only required North Korea to mothball its Yongbyon reactor; this time Pyongyang is required eventually to dismantle the reactor and its reprocessing facilities, as part of a general programme of nuclear disarmament. To save face all round, it is described as the “implementation” of North Korea’s offer, in 2005, to give up its nuclear weapons. But that was a vaguely worded commitment “in principle”. This time, Pyongyang is committed to a timetable, at least initially. It has 60 days to seal the Yongbyon plant, admit UN International Atomic Energy Agency inspectors and disclose its nuclear programmes. No more than 5 per cent of the promised oil will be delivered before March 19, when the six-party talks reconvene to assess progress. The next phase, which has no timeframe, requires it to disable all nuclear facilities — those the world knows about and those it does not.

North Korea may not mind losing Yongbyon; it has almost certainly finished reprocessing the nuclear fuel rods that were stored there — perhaps enough material for around ten bombs. The stiffer test is its agreement to disclose, before dismantling, all its programmes. Until there is verified progress on that front, the UN sanctions should remain firmly in place. The US should unfreeze only those North Korean bank accounts abroad that are clearly for legitimate trade, not counterfeiting and smuggling. Pyongyang may have signed this agreement, believing it can once again hoodwink the world. It must be made to understand that the rules are different this time and that Beijing is the referee.