This chapter explores how IR has been imagined and reimagined in relation to the concept of the border of the state. The chapter presents an overview of how that concept has operated within contemporary IR theory: as an assumed ground in traditional approaches and as a site of inquiry and repoliticisation in more critical work. By highlighting the contingency of borders and their intrinsic relationship with violence it is argued that we can denaturalise present structures and sites of political authority. As such, Walker argues that it is precisely this spatial temporal resolution provided by the logic of inside/outside' that makes orthodox theories of IR distinctive. Whereas the former centres on the study of territory and power, the latter has urged, following the work of Michel Foucault, closer attention to the relationship between techniques of government and the management of populations.