This Risk Report highlights the Mekong River as an influential factor with regards to security and economic implications for riparian Southeast Asian countries. This report is framed by the construction of Chinese hydroelectric dams near the source of the river that allows them unparalleled control over the river’s flow. To understand the issues, the Mekong and its importance to the economies of the downstream countries is first explored, namely: Myanmar, Laos, Thailand, Cambodia, and Vietnam. Subsequently, a discussion of the multilateral forums in place which provide a form of regional governance for the relevant countries. This is followed an examination of Chinese ambitions along the Mekong and a survey of several of the larger dams that exist along the river. Lastly, an assessment of the implications of Mekong dams through security, economic, and environmental lenses is provided.