In a world that is increasingly interconnected, the very concept of security requires redefinition and broadening. Dan Caldwell and Robert Williams not only offer a cogent explanation for why this is the case, they also present an excellent overview of the range and nature of the new threats. In doing so, they have provided a real service to scholars, policymakers, and interested laypeople alike. Scholars will benefit greatly from the discussion of why traditional state-based threats are limiting and a new security paradigm incorporating non-state threats is needed. Policymakers will gain from the analysis of the character of new threats, the danger of unintended consequences when employing traditional military responses to them, and the value of new forms of cooperation for containing and combating them. And interested citizens, after reading this thoughtful book, will both understand the challenges of security in a new century better and also be able to demand more imaginative and integrated responses from governments and non-governmental organizations. (Previous Edition Praise)