‘As so many knowledgeable observers have said, the next war will be over water. People can survive without oil, but not without water.’ Thus wrote peace research veteran Johan Galtung in 1991 (What would peace in the Middle East be like, BPP 22(3): 246). Knowledgeable observers notwithstanding, it is hard to label any of the multiple wars fought in the Middle East since 1991 as having water as the only or even the main issue. Water does indeed play an important role in this  book, but in a more nuanced way. Ashok Swain devotes a whole chapter to water conflict and cooperation. Climate change can result in major changes in the water cycle, leading to an increased risk of water-related natural hazards – floods, or droughts and water scarcity. This can impact agriculture and economic development, in turn weakening the position of governments unable to deal with the crisis. Such changes can also undermine international treaties about water-sharing in cross-boundary river basins. Yet, the author perceives a beacon of hope in that crises also can lead to increased cooperation. The author adopts a wide conception of security, placing the individual at the center, emphasizing the protection of people ‘from critical and pervasive threats to human rights, safety and even survival.’ Given this starting-point, it would be surprising if climate change did not have a potential for increased insecurity. Swain could have paid more attention to the quantitative literature, but on the whole his book provides a broad and readable survey of ways in which climate change can impact human and even national security. It ends with a call for bold and decisive international cooperation.