With their methodology and their destructive effects, comparable to those of acts of war, the new forms of terrorism are often categorised as asymmetric threats, as they tend to catch unawares peacetime security systems, usually not designed to counter activity on such a scale, as also military defence systems, whose use is constrained by the peacetime legal framework. France’s White Paper on defence and national security takes these new forms of threat into account, and sets out recom­mendations to limit their effects, if they cannot be prevented entirely. Amongst the potential targets that can be categorised as ‘high value’ are those installations, such as military nuclear deterrent systems, that present major environmental risk in the event of so-called ‘disproportionate aggression’. If we are not on guard, the new asymmetric threats can circumvent these systems, for the most part designed to meet threats of a military nature.