The Association of Southeast Asian Nations (ASEAN) was originally formed in 1967 by five members as a means to promote peaceful relations and prevent the spread of communist influence within their sovereign states. Since then the regional organization has doubled in size and now includes communist states amongst its membership as it seeks to establish itself as a strong economic and political hub for the greater region as two large military powers, China and the United States, vie for hegemonic influence. The American presence in the region must be governed by a firm understanding of ASEAN's unique nature and goals. When compared to other regional organizations that formed over similar time periods, such as the European Union, ASEAN has not taken a cohesive path with less of a firm timeline for integrating institutions as it instead continues to reshape its policies in small iterative steps to evolve to the changing world. If our existing paradigms of the role of regional organizations do not match with the structure of ASEAN, we must establish a new toolset in order to guide future policies for involvement in the region. This thesis seeks to provide a clear description and thus understanding of the institutions and behavior of ASEAN as a regional organization. The questions posed include whether ASEAN conforms to the institutional and behavioral predictions of the major paradigmatic approaches to international theory, namely realism, liberalism, and constructivism. The thesis begins with a brief history of ASEAN over four distinct phases and an overview of regional organizations and international theory. The three dominant theories are then analyzed in their application to ASEAN in the areas of security, economics, and human rights. Conclusions are drawn that each of the three theories has its value for descriptive insight, but all fall short in creating a holistic understanding of ASEAN. Therefore, I propose a new way of describing ASEAN as a reactive, isomorphic, and anti-fragile regional organization. The potential of this approach is that it utilizes tools latent in the existing theories to examine ASEAN's nature.