The concept of Regional Security Complexes (RSCs) illustrates Buzan’s big picture approach par excellence. It allows the mapping of regional security interactions across the globe, and combines such a bird’s-eye view with the interactions between different security actors and middle-range hypotheses, for instance about the likely behaviour of insulator states. It also exhibits Buzan’s approach of combining traditional theoretical arguments (the systemic relevance of regions) with more critical and constructivist work (securitisation theory). In the context of the post–Cold War world, RSC Theory (RSCT) became quite popular. Yet the parsimony of the argument came at a price. The impossibility to empirically chart the actual security interactions meant that Buzan and Wæver had to give up on one of the core pillars of securitisation analysis, lending weight to those critics who had accused them of privileging states as security actors. Furthermore, the quasi-structuralist inclinations of RSCT underestimated the agency of insulators such as Turkey. This contribution traces the development of RSCT and explores its ambivalence in analytical and normative terms. It argues that RSCT is indicative of Buzan’s contribution to the wider discipline, yet also of some of the limits of his oeuvre.

This book has had two main aims. The first has been to make the case for a particular approach to understanding the concept of security – namely, by suspending prior belief as far as possible and attempting to rethink it from philosophical first principles. The second has been to demonstrate that approach by reconstructing a detailed account of security in precisely that vein and exploring its real-world implications.