The shift from probabilistic to possibilistic risk management characterises contemporary cultural attitudes towards uncertainty. This shift in attitude is paralleled by the growing influence of the belief that future risks are not only unknown but are also unknowable. Scepticism about the capacity of knowledge to help manage risks has encouraged the dramatisation of uncertainty. One consequence of this development has been the advocacy of a precautionary response to threats. This article examines the way in which precautionary attitudes have shaped the response to the threat of terrorism and to the millennium bug. The main accomplishment of this response has been to intensify the sense of existential insecurity
