Drawing on the changing landscape of responses to HIV in Vietnam, this article describes the key players and analyzes the relationships between global players and local interests, including both the omnipresent state and an emerging civil society presence. We discuss the critical importance of timing for policy intervention and the role of health policy in shaping the broader social terrain. The interventions of external actors such as the US President's Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund were instrumental in improving both policies and programs at a critical juncture, when the national responses to the epidemic had been ineffective. At the same time, those global interventions met resistance and led to unintended consequences, both welcome and unwelcome. Furthermore, the looming specter of donor withdrawal and the very gradually emerging national ownership raise many questions about capacity for scale-up and sustainability of the significant achievements to date. Further monitoring and in-depth analysis of the Vietnamese responses to the HIV epidemic in the next few years or so, we contend, have the potential to provide unique insights into the challenges faced by developing countries caught in the complex webs of health politics and policies at both the global and the national levels.