This chapter aims to take stock of the research programme that has emanated from the Democratic Peace thesis and that is best described as a democratic distinctiveness programme. This usage emphasizes the finding that democracies tend to differ from non-democracies in the conduct of their external relations. The chapter reviews the literature that is inspired by the democratic distinctiveness programme and that addresses three prominent developments in post-Cold War security politics: the broadening of the concept of security, the changing nature of Western warfare and the internationalization of security politics. It examines the extent to which democracies, rather than functional requirements, technological innovation, or shifts in the global distribution of power, have been put forward as the driving force behind these developments. The chapter explores the contributions of various approaches and International Relations (IR) theories to the ever-expanding field of security.