The habitual bundling together of defence and security contributes to confusion and can result in serious misunderstandings. Defence is the concern of the armed forces—that is, the military. Defence contributes to territorial security against external aggression, or possible internally-fomented insurrection, and is complemented by the civil component of public security, represented by the police and the various forces for the maintenance of public order which support them. The importance assumed by the struggle against terrorism over the last ten years should not allow us to lose sight of the fundamental difference between the players and their respective tasks. The general idea of security is intended to be all-embracing in order to cover a variety of areas affecting individuals’ lives. So we speak of ‘human security’ and ‘non-conventional security’, which increases the ambiguity and we end up forgetting to define the players in this security business. A tsunami, or a large-scale financial crisis affects prosperity. Climate change or pollution compromises everyone’s quality of life, across frontiers.

Similarly, international terrorism, no matter how reduced and circumscribed it may be, constitutes a persistent threat, for a generation at any rate. It affects the effort to relate the nature of the danger with the identity of the players involved. The police and the justice system play the main role within national territory and with their foreign counterparts, but if it becomes a matter of far-flung operations to reduce or wipe out training camps, or bringing law and stability to violent regions, the judge or the policeman alone will not be up to the task. Here, the armed forces come into play.

Massive and uncontrollable immigration affects security because it is destabilizing and threatens traditional balances, which are in any case often precarious. The disruption of supplies of energy and strategic raw materials can threaten the very existence of nations and peoples. In these cases, a resort to armed force may turn out to be necessary once the diplomatic process has been exhausted.