An international river basin is an ecological system, an economic thoroughfare, a geographical area, a font of life and livelihoods, a geopolitical network and, often, a cultural icon. It is also a socio-legal phenomenon. This book is the first detailed study of an international river basin from a socio-legal perspective. The Mekong River Basin, which sustains approximately 70 million people across Cambodia, China, Laos, Myanmar, Thailand and Vietnam, provides a prime example of the socio-legal complexities of governing a transboundary river and its tributaries. The book applies its socio-legal analysis to bring a fresh approach to understanding conflicts surrounding water governance in the Mekong River Basin. The authors describe the wide range of uses being made of legal doctrine and legal argument in ongoing disputes surrounding hydropower development in the Basin, putting to rest lingering caricatures of a single, ’ASEAN’ way of navigating conflict. They call into question some of the common assumptions concerning the relationship between law and development. The book also sheds light on important questions concerning the global hybridization or crossover of public and private power and its ramifications for water governance. With current debates and looming conflicts over water governance globally, and over shared rivers in particular, these issues could not be more pressing.