In the first chapter of this book, a comparison of key cosmopolitan and communi tarian thinkers provoked two significant questions about the current state of inter national relations. The first question was whether recent trends are best interpreted as progress towards global democracy, as some cosmopolitans claim, or are better described as a Walzerian ‘universal moment’ reflecting the communitarian nature of international politics. The second question concerned the role of worldwide, authoritative mechanisms for peaceful change in international affairs. Was the claim correct that incremental efforts towards a cosmopolitan democracy were ‘desirable’ per se, or were the communitarians right to emphasise just how restricting the absence of these mechanisms were for cosmopolitan objectives? Before examining what the study of the concept of aggression undertaken here tells us in response to these two questions, it is first necessary to consider developments relevant to aggression which have taken place since 1998.