The attacks on September 11th, 2001 are a sophisticated technical operation in their aims as well as in their elaboration, their coordination, and their execution. At the same time, the attacks have dramatically proved the vulnerabilities of open and developed societies, especially the limits of the security technologies they use against major threats. Thus, not only was all of the United States’ security technology unable to detect and prevent on time acts which were deemed possible and whose potential targets were even suspected, but moreover, it has been used by terrorists to create strong perturbations. This is why now is the time to proceed to a qualitative, more than quantitative, re-evaluation of collective security means, in order to avoid the very technological drift which created the fragility used by those responsible for the attacks on September 11th. – Summary AFRI-2002