Considerations of risk are pervasive in the contemporary security environment. A risk is a scenario followed by a policy proposal for how to prevent the scenario from becoming real. When policy makers approach security questions in terms of risk, they no longer seek to address specific and calculable threats like the Red Army during the Cold War. Instead, they focus on trends that give a future significance to present challenges—trends that give future significance to present challenges include (a) the personalization of risk, (b) the establishment of political community based on risk, and (c) existential risk where the fate of humanity is at stake. In his 1958 book War and Industrial Society, Raymond Aron claimed that industrial society had shaped not only the way in which war was fought in the 20th century, but also the expectations of what force could achieve and how peace could be made. A number of sociologists argue that the industrial society described by Aron is changing into what Ulrich Beck terms a risk society. Risks are associated with a decision. Risk is inside politics, not outside—both internationally and domestically. Risk studies therefore often focus on the difficulties and dilemmas confronting policy makers as they struggle to provide security in a post-secure society. Risks are continuously identified by scenarios pre-empted by military actions or other acts of security—only for the results of these actions to produce, in turn, new risks. The article seeks to explain why risk studies have never coalesced into a coherent research program, as perhaps some of the scholars engaging with risk theory hoped it would. Having concluded that risk theories remain fragmented and more engaged with particular subfields than with each other, it makes sense to deal with the substantial contribution of risk theory by focusing on particular trends in security policy in which the risk perspective has something important to say.