This is a highly recommended study. It shows how Allied assistance to resistance movements was political and complex but also iterative, consisting of mistakes, clashes, compromises, and transformations. Piffer surveys archival and published primary sources in several languages, synthesizing a wide body of literature to provide a new look at actors and events. The book draws from military and intelligence studies, but focuses on the political and international aspects of Allied support for resistance to Nazi Germany. There was much detail, but findings and arguments to frame the events were often absent. More analysis would have helped connect the research to the broader literature. Nevertheless, this book is an invaluable contribution to scholars interested in intelligence studies and internationalrelations during the Second World War.