Since January 2004, several members of the Benchellali family have been held on such charges, linked to plans for a chemical bomb.

ECONOMIST: France

Not least, since technology seldom works flawlessly and there are plenty of other ways of delivering a nuclear, chemical or bug bomb, any future defences have to work in ways that strengthen deterrence and diplomacy the traditional means of dealing with threats to peace not undermine them.

ECONOMIST: Bush??s nuclear umbrella

The UN's resolution 1540 obliges all governments to stop nuclear (and chemical and biological) bomb-making materials falling into terrorist hands.

ECONOMIST: Preventing nuclear trafficking is easier than policing it