Wasserstein, a medieval historian, explains key components of the Islamic State's (ISIS) ideology and many of the group's practices, mostly through the lens of early Islamic history, an approach that produces interesting insights.
For instance, he offers a detailed analysis of the Islamic State's proclamation of the caliphate in June 2014, explaining the significance of the caliphate in Islamic history and why ISIS placed such emphasis on citing Qur'anic proof texts. In addition, he provides useful context to the apocalyptic traditions surrounding the Aleppo province town of Dabiq, which featured prominently in ISIS propaganda.
Other sections of the book are less original or lack detail. For example, the analysis on recruitment of children has little new. Wasserstein also devotes just twelve pages to Islamic State administration, though analysis of its government departments and in-depth comparisons with past and present models would have been useful.
The book is also outdated. The Islamic State no longer controls a territory the size of the United Kingdom. Despite useful historical background on the Dabiq tradition, references to Dabiq by ISIS have now faded since the group lost control of the actual town. Indeed, the group long ago ended production of its Dabiq magazine.
Further, Wasserstein makes sloppy errors. He devotes an entire sub-section to the tarawih (extended prayers in Ramadan) based on the erroneous claim that ISIS banned it. Similarly, he writes that the Islamic State's Sinai affiliate attacked a hotel in retaliation for the Egyptian government's imprisonment of "female IS fighters," but the New York Times report he cites and the original ISIS statement on the assault make no reference to "female IS fighters," only "Muslim women" arrested by the Egyptian army. Other errors reflect insufficient research: the "al-Badri" in Abu Bakr al-Baghdadi's full name does not refer to the battle of Badr but rather is an Iraqi tribal name.
Wasserstein's book takes the Islamic State's religious ideology seriously and makes interesting comparisons with early and medieval Islamic history for insights into how the group thinks and operates. But its noteworthy approach is beset with multiple flaws.