As part of its broader multiyear effort to explore the contours of Asian institution building, the Stanley Foundation, in collaboration with the Institute on Global Conflict and Cooperation (IGCC), convened a workshop on February 12, 2008, to explore the way forward for a future multilateral security and peace mechanism in Northeast Asia and the near-, medium- and long-term implications for the United States. This workshop built on an earlier IGCC-Stanley Foundation meeting on envisioning the future security and peace mechanism for Northeast Asia held in November 2007 in Moscow. The establishment of a Northeast Asian Peace and Security Mechanism (NAPSM) is envisaged as part of Phase 3 of the six-party process (which would also include the full dismantlement and abandonment of North Korea’s nuclear weapons capabilities along with numerous other related issues such as the normalization of US-DPRK relations and the parallel drawing up of a separate peace treaty for the Korean peninsula). Given the uncertain status of the six-party process, the future of a NAPSM is likewise uncertain but, nonetheless, discussion and debate is already well under way addressing a variety of the functional and institutional design issues that need to be taken into account if the idea of a Northeast Asia regional security organization is to get further consideration. This includes how to best create or evolve such a mechanism, the principles that might guide and animate such an organization and, indeed, what sort of institutional structure is most suitable given the mechanism's goals, as well as how to incorporate the military and economic challenges of the region. This Policy Memo, drafted following the San Diego workshop, provides a brief overview of the issue and factors at play for US policymakers.