This chapter introduces Foucault’s idea of genocidegenocide as a form of mastery over the temporal process of “social speciation” and contrasts that with Jacques Sémelin’s understanding of genocide as racial or national purification. For Foucault, security is above all a species concept. If control over speciation, or biopower, is the goal of modern sovereignty, “security” refers to the means by which that goal is to be reached. As such, “security” covers the production of subjectivity, which is exercised over a “milieu” or “area” that is not simply defined by territory. In other words, “security” is not based on a calculation of aleatory risk or imagined impurities in the social body but is rooted rather in a project of sovereign control over speciation via an apparatus of area and anthropological difference. Sovereign is the one who controls speciation, both at the level of the individual and at the level of the population. Control of both of those levels hinges on subjective formation. Inability to control speciation is tantamount to a loss of sovereignty that incurs insecurity.