Invitation to Terror: The Expanding Empire of the Unknown Book

Much of this book consists of clearing out the weeds that infest the field of research about terrorism. Key terms (including "terrorism") are poorly defined; some writers assumed terrorists were pathological, and most others accepted that assumption uncritically; the relative scarcity of data for such a complex and politicized subject leads people to substitute profound-sounding metaphors for actual research; etc. Those parts alone make the book vitally important for anyone doing further research. The main messages may be summarized quickly: Terrorists are unremarkable; terrorism includes multiple aspects, all of which are complex; it may perhaps be profitably approached by considering the processes terrorists undergo, which may be grouped in terms of involvement, engagement, and disengagement. There are no simple answers to be found, and generalities are never all that general. Horgan tells of another terrorism researcher who noted that the better the study, the more muddled the findings. I would not describe Horgan's book as "muddled" exactly, but it will not satisfy people looking for clarity of the whole subject. It should, however, serve as a solid starting point for further research in the field.