Constructivism’s focus on how the world hangs together, how normative structures construct the identities and interests of actors. And how actors are rule following, might seem ideal for explaining reproduction but useless at transformation. This is hardly true. Because constructivism claims that what exists need not have and need not that is, it invites us to think of alternative worlds and the conditions that make them more or less possible, constructivism scolded neo-liberal institutionalism for their failure to explain contemporary global transformations. The peace of Westphalia helped to establish sovereignty and the norm of noninterference, but in recent decades various processes have worked against the principle of noninterference and suggested how state sovereignty is conditional on how states their populations. World orders are created and sustained not only by great power preferences but also by changing understandings of what constitutes a legitimate international order. Until the second world war the idea of a world organized around empires was hardly illegitimate; now it is