This article examines the civil society campaign to stop the construction of a military base in South Korea as a case study in both the promises and limits of global advocacy networks in the digital media age. First the article traces the historical and political contexts leading up to the 2007 decision by the South Korean government to locate the naval base on the coastline of Jeju Island, despite strong objections from residents of the targeted village. Then the article illustrates how local activists fighting the base gained support in the global peace, justice, and environmental movements, even if the larger protest campaign and the international media coverage it generated did not stop the project. The case illustrates how the notion of the ‘global public sphere’ remains highly contingent upon the readiness of local and global political actors to anticipate and overcome the persuasive and coercive powers of national governments as well as national political cultures that can enable authoritarian tactics to stifle public debate. It also illustrates how activists in the global justice movement often run into formidable obstacles when confronted by centralized political and economic power in specific national settings.