Nature: Geoff Brumfiel asks in this week's Nature whether US plans to limit North Korea's exporting opportunities of its nuclear technology will work. Secretary of State Condoleezza Rice has been meeting leaders from neighboring countries to discuss ways to detect and intercept illicit nuclear stocks but some proliferation experts doubt that the screening regime is practical or even possible. A particular concern is that North Korea might smuggle nuclear material to other states or terrorist groups, says Michael Burns, principal deputy for threat reduction at Los Alamos National Laboratory in New Mexico. If terrorists do get hold of a nuclear bomb says Michael May and Jay Davis in a commentary write in the same issue, it will be crucial to know where the terrorists got their material. In that regard, they propose that the international community should consider expanding the IAEA existing database of nuclear explosives to develop the field of nuclear forensics. "Establishing the data bank proposed here would greatly reduce the time between this most terrible of events and the ability to respond to it," says Davis and May.