This book provides an interdisciplinary approach for considering international water management under conditions of increased scarcity and variability (both present and future as a result of climate change). The book applies a theory that is rooted in the disciplines of international relations and economics to the analysis of scarcity, variability, and cooperation over transboundary freshwater. It demonstrates the usefulness of the theory using global datasets of transbounary water bodies (documented treaties, water availability, water variability, water-related events) and in-depth case-studies of specific basins. By doing so, this book provides a framework that allows scholars and policy makers to reflect on various future scenarios and assess the impact of policy interventions on the regional and global level, with implications for conflict and cooperation. Finally, the book also considers strategies and other forms of incentives that help assuage conflict and motivate cooperation despite scarcity and variability.