'International Law and Policy on the Protection of Civilians is a masterful guide to the multiple legal, political and normative influences that are transforming our understanding of obligations to protect civilians from violence. The result is a rich depiction not only of sources of civilian protection, but of the complex ways in which expectations evolve in a decentralised international system. Casey-Maslen and Vestner have rendered an invaluable service by preparing a volume that will be indispensable to state officials, military leaders, non-governmental organisations and anyone who cares about protecting the innocent from the ravages of conflict.' Mitt Regan, McDevitt Professor of Jurisprudence, Co-Director, Center on National Security, Georgetown Law Center