This book is a careful, innovative, well written, and deeply informative contribution that demystifies a large part of the world. Although there are only 37 Islamic law states, Powell justifies her study by arguing that nearly a quarter of the earth’s population adhere to some extent to a tradition that is ’ethically, morally, doctrinally, or politically committed to sharia’ (p 1). Powell investigates how these commitments shape the engagement of Islamic law states with international law. Half of the book is devoted to the careful exposition of key concepts and categories. Because she is interested in international law, Powell focuses on how Islamic law traditions handle the peaceful settlement of disputes, and particularly territorial disputes. International resolution of territorial disputes has been studied extensively in political science, allowing Powell to compare Islamic law states to non-Islamic states. Much of the book focuses on explaining variation between Islamic law states, and this investigation dispels crude generalizations that suggest that Islamic law is a monolithic ’other’ that is vastly different from Western law. Powell finds distinct elements that are common to Islamic law, along with similarities to Western legal systems that allow Islamic legal systems to be studied comparatively. Powell is a social scientist at heart, but her larger objective is to help Western readers appreciate admirable features of Islamic law, and to find common ground. Powell is right that Western law needs to bend if international law is going to be inclusive and legitimate in the eyes of different peoples. Her book charts a path towards this goal.

(A longer review will be published in Governance: An International Journal of Policy, Administration and Institutions.)