The hard-won nuclear deal with North Korea seems to be unraveling after a hopeful period in which the North shuttered its nuclear reactor at Yongbyon and dramatically blew up the cooling tower. Workers stopped dismantling the complex last month, after the US failed to take North Korea off the terrorism list — a step toward diplomatic rehabilitation. Now technicians at Yongbyon are preparing to restart a plant that makes weapons-grade plutonium.

North Korea’s leader, Kim Jong-il, is notoriously erratic, and there are reports that he may be seriously ill, raising doubts about who is calling the shots. It has never been clear whether Pyongyang really meant to give up all of its weapons. In this case, the Bush administration bears much of the blame. Vice President Dick Cheney and other administration hardliners have never wanted to negotiate.

Now the administration is insisting that before it will remove North Korea from the terrorism list, Pyongyang must first accept a plan for verifying its nuclear programmes that only a state vanquished in war might accept. We believe that North Korea must give up its weapons and get out of the business of selling nuclear technology and know-how. We don’t know if that will ever happen. If there is any chance at all, it will require both vigilance and flexibility.