The regionalism in Southeast Asia based on the Association of Southeast Asian Nations (ASEAN) had outstanding characteristics during the Cold War period. First of all, it emphasized the sovereignty. The basic principles of international law in which sovereign equality was the core became behavioral norms of ASEAN member nations. The principles of respecting for sovereignty, non-interference in each (other's) internal affairs and pacific settlement of disputes were observed and upheld in regional cooperation. Secondly, the basic content of the regionalism in Southeast Asia was the cooperation i...