I read this in tandem with Adonis' Introduction to Arabic Poetics, which I'm burning to write about. But this, it was a fascinating "in-the-weeds" analysis of the origins and overwhelming resilience of Salafi-Jihadism as a soteriology and political doctrine. The book is structured around specific categories that Maher describes as forming the Salafi-Jihadist project of "progress through regression" - itself a brilliant way to put it, and approach thinking about it.

The categories as I've previously noted were:
"al-walā wa-l-barā", the lines of loyalty and disavowal for the sake of Allah.
"takfīr", which delineates Islam against everything else and protects it against insidious corruption from within. e.g excommunication, banishment from the faith.
"tawhīd and hākimiyya" which explain what legitimate authority should look like and who it should serve. e.g how God's sovereignty is established within a political system.
and "jihad", the method of revolution. Literally means to exert of effort or struggle but also has a legal definition of combat or fighting.

I found this book comprehensive and considerably deepened my understanding of the current conflict in Syria, its international implications as per global terrorism and the various regional conflicts of the last three decades.