Horowitz has written a scholarly analysis of why some governments enthusiastically embrace military innovations while others miss out. He identifies two main factors that determine a state's capacity to upgrade: the ability to afford the improvements and the organizational capital to adopt them. Both factors are normally important, but their relevance can vary. To become a nuclear power requires a considerable financial outlay but not much organizational change. Aircraft carrier warfare is both expensive and organizationally demanding. Adopting suicide bombing is a cheap tactic for a terrorist group but requires major organizational changes. Horowitz has successfully built on existing theories of organizational change and military innovation, but he might have made more of strategic considerations, which provide the impetus to spend both financial and organizational capital. His consideration of suicide bombing as a military innovation is imaginative, but his suggestion that the Catholic Provisional Irish Republican Army, which had to beware of Protestant paramilitaries, somehow missed a trick by not adopting this tactic betrays a gap in his research. The book also suffers from the curse of American political science in its occasional use of complex statistics to make unremarkable points.