The study covers two regions. These are shown to constitute ‘Regional security complexes’. The Gulf region and the Gulf Cooperation Council (GCC) and the Association of Southeast Asian Nations (ASEAN) in the Southeast Asian region are the focus of study. The defence and security circumstances of the two regions and the responses of the regions’ governments severally and cooperatively are examined. The study has had to take account of the geographic, historical, ethno-cultural differences between the two regions. These are shown to be influential in their respective security responses. Nonetheless, the thesis demonstrates how the regions can be understood in terms of a common theoretical framework. The study is undertaken primarily within the framework of the theory of ‘Regional Security Complex’ (RSCT), as developed by Buzan and Waever in Regions and Power. Regional security complexes are areas of internal “security interdependence” and securitisation. The theory (RSCT) is discussed critically. ‘Security Communities’ is a major comparative feature of the study. Amitav Acharya develops this approach in Constructing a Security Community in Southeast Asia. Emphasis is on the “creative construction” of a ‘security community’. The Gulf Cooperation Council may also be viewed in this way. ‘Regional security complex’ and ‘regional security community’ are not alternative theories of regional inter-state relations. The second is superstructural on the prior facts of regional security complexity. The GCC is a partial response to regional security and is a securitising actor in the region. ASEAN is an attempt at region-wide inclusiveness and conflict avoidance. Institutional management of security is described. The two regional approaches differ as beliefs that the “enmity/amity balance” is amenable to official regional policy and action: the Gulf and GCC are apparently locked in a dominant ‘enmity’ scenario; ASEAN seeks to establish a regime of ‘amity’. Whether ASEAN is notably less militarily oriented than the Gulf is questioned. States’ insistence on national security ‘resilience’ and ASEAN norms of ‘sovereignty’, ‘non-interference’ and conflict avoidance’ impede regional security development. ASEAN’s progress towards an ‘ASEAN Security Community’ is examined. The study discusses practicalities of these policies. The application and limitations of ‘Revolution in military affairs’ (RMA) are discussed. The military are viewed as a principal operational actor in any regional security response to conditions of regional security complexity. An examination of state-military relations is based on the concepts of ‘grand strategy’ and ‘military doctrine’.EThOS - Electronic Theses Online ServiceGBUnited Kingdo