A slender monograph on an increasingly salient topic. Entrepreneurs and huge international companies have edged their way into not just equipping armies, but into training, supporting, and working for them as well. This study merely scratches the surface, and the notorious examples (notably Executive Outcomes of South Africa) get most of the attention. The author does not tell us as much as we might like to know about what these organizations actually do or how they are staffed -- not surprising, perhaps, given their interest in keeping their operations secret. As an appetizer for a more substantial work, however, this is an intriguing study.