Writing a thesis is like writing a story book, this book is a story of the 17-year-old Asia-Europe Meeting (ASEM). It serves as a case-study of inter-regionalism, one of the newest cooperative mechanism in today’s international arena. Among a variety of cooperative frameworks, namely, multilateral global governance, effective multilateralism, regionalism, regionalisation, inter-regionalism is much less explored. This research determines how the rise of inter-regionalism influences the actors in the international arena and vice-versa. The key actors in inter-regionalism and their interaction are explored. Existing studies in the field of inter-regionalism in general and on the ASEM process in particular have been theory-led. There is a significant deficit of empirically-driven research in the field. In order to comprehensively understand inter-regionalism and the ASEM process, this research incorporates a substantial empirical focus. An unprecedented array of primary data is used. A variety of quantitative and qualitative data collection and analysis methods are employed to generate this unique and comprehensive empirical analysis of ASEM. Ultimately, this thesis demonstrates the persistent state-centrism and lack of actorness of regions and regional organisations as independent actors in the ASEM process. Nation-state remains the primary actor in inter-regionalism; yet, they turn to bilateralism when more concrete cooperation or affairs have to be handled. The proliferation of sideline meetings, although as by-product, becomes one of ASEM’s key added-value to international relations. The empirical analysis also finds that inter-regional fora like ASEM offer participants regular information and views updates and promote socialisation among government officials in the official track and among the involved individual from civil society in the unofficial track.