Water is essential for all aspects of life. Managing water is a challenging task, particularly in shared water basins that host more than half of the world's population. National sovereignty and security considerations have long constrained the reasonable, equitable and sustainable utilization of international water courses. With post-Cold War democratization and globalization on the rise, domestic actors have an increasingly important role to play in national decision-making and traditional foreign policy debates. This volume explores both these threats and opportunities through the presentation of case studies that analyze the multi-faceted and dynamic nature of the interplay between domestic and international water security.