Northeast Asia, covering China, North and South Koreas, Japan, Russia, and the US, is a region of opportunities and challenges. On the one hand, after the financial crisis in East Asia in 1997, the building of an East Asian community, centered on ASEAN Plus Three (APT), became an important agenda item among political leaders and in scholarly circles. The Association of Southeast Asian Nations (ASEAN) has played an important role as a nodal point to facilitate economic cooperation between ASEAN and the three countries-China, South Korea, and Japan. In other words, the three countries have apparently taken advantage of the bandwagon of an established multilateral cooperative institution, ASEAN. On the other hand, contentious security issues in Northeast Asia lie before such a bright vision of regional integration. North Korea’s nuclear development and the unstable situation in the Taiwan Strait are facets of the security problem that interferes with the building of a regional community. Also, that the US, which maintains a great deal of influence on regional security affairs, adheres to bilateral security alliances is a serious challenge to the movement toward the ideal of regional community.