Transregional security cooperation after September 11, 2001

The aim of this article is to answer the question what kind of global security architecture emerged after September 11 and what functions Europe, East Asia and the United States assumed in this triadic structure. The empirical findings reveal that the transpacific security cooperation is the strengthening link in this global security structure, the transatlantic security cooperation the weakening one and the Asia-Europe Security Cooperation is to be seen as the emerging link. In order to explain these different institutional manifestations of transregional cooperation, different theories of International Relations are applied to the three cases. It comes as no surprise that neoinstitutionalism and constructivism offer the best insights into the formation and development of international institutions. © Springer-Verlag 2005.