Accounts of regional co-operation have been provided by a range of scholars from a host of theoretical perspectives. Rationalist approaches tend to focus primarily upon the distribution of material power capabilities and the impact of changing structural conditions and to assess the relative gains to be made through collaboration in order to maximize self interests. However, this chapter adopts a broadly constructivist perspective. In this way, it focuses primarily on the role of ideas and interests in the creation of regional identity and the development of a sense of “we-ness”. In fact, a range of cultural and sociological perspectives in International Relations has opened up an entirely new way of looking at inter-state relations and the formation of international norms and institutions. Indeed, this has permeated some of the rationalist literature, which itself has acknowledged the role of ideas in the formation of foreign policy. Several forms of constructivism take these approaches one step further, by focusing on critical historical junctures from which new structural or institutional arrangements, norms and identities emerge and on interactions between existing structures, institutions, norms and agents. In particular, many constructivist assessments also permit a focus on the mutual constitution of structure and agent, thereby breaking down what are often unhelpful distinctions between an actor and her environment.

Although there are many forms of constructivism and it cannot lay claim to be a coherent body of theory, this chapter draws on the “mainstream” interpretations by scholars like Wendt and Katzenstein, which permit a continued focus on the state, while examining the multi- level identities it may adopt. The constructivist approaches with which this chapter is concerned respond to Katzenstein's observation: “Power politics is now occurring on complex regional contexts that undercut the stark assumption of the international system as unmitigated anarchy and these regional contexts are making possible a variety of processes that put into question some conventional categories of analysis.”