This book is pitched at a reasonably high level, but is still quite readable. The initial chapter on guerilla theory, and the concept of the titular "Accidental Guerilla", is worth the cover price alone. This concept is then backed up with case studies in various hotspots around the world.
The book gives a fantastic insight into insurgency in general, and takfiri (to use the preferred phrase from the book, instead of Islamist) insurgency in particular. The reasons for the global spread of the "War on Terror", and how the US and NATO have unwittingly assisted in some cases, are clearly presented and quite compelling.
Anyone who has an interest in the conflicts of the current era should read this book. Anyone who is involved in these conflicts - soldier, statesman, diplomat - MUST read this book.