This article examines the prospects for the realization of the agreement signed at the 2007 inter-Korean summit to transform the conflict-susceptible Northern Limit Line (NLL) in the West Sea into a border area where South and North Korea jointly promote peace and prosperity. To realize this agreement the two Koreas must integrate new ideas and plans by viewing the NLL as a space of common benefit rather than a line of military confrontation. The establishment of the West Sea Special Zone for Peace and Cooperation focuses on security and economic issues. Implementation of the agreement requires particular attention to development of a comprehensive plan, including promotion of ecological, environmental, historical, and cultural assets, as well as inter-Korean fishery cooperation.