After myriad studies on military manpower policies, especially on conscription versus volunteer service, this excellent study brings something new: a historical, philosophical and geopolitical approach that goes well beyond the policy issues of the day. The author, a professor at Harvard, has done a superb job in identifying the cross-cutting foreign policy constraints, military requirements and ideological assumptions which have made it almost impossible for the United States (unlike many other Western nations) to settle on a durable system of peacetime military service. Cohen argues that for the U.S. a successful military manpower system must be consistent with "liberalism" and "egalitarianism," i.e., service should be limited in duration and required of all. But it also has to provide effective forces for large and small wars. This is a difficult circle to square.