An incredible, timely book. Kilcullen was a major participant in the formation of strategies used in our wars in the Middle East/Africa. He readily acknowledges the mistakes that "we" made; by concentrating on the theory of "disaggregation" (mainly going after the leaders of Al Qaeda, it was assumed that it would break up the group into smaller entities, which local the local government could deal with, but in reality it just dispersed the group to other areas and allowed them to start up new groups, including ISIS).
That our practices, such as "extraordinary rendition", undermined our standing as the "good guys", drove a wedge between us and the locals, and made it very hard to pressure other regimes into encouraging human rights (do as we say, not as we do). By shifting our focus from terrorism to Iraq, we alienated allies; and after our reasons for the invasion were proven falsehoods, it made it hard for others to trust our "intelligence". How (Rumsfeld) insistence on using the minimum force in Iraq was a disaster, our disarming of the Iraqi army and the Ba'athists created a large, potentially useful group into enemies (who ended up forming future terrorist organizations). Kilcullen goes so far as to likening "Bush's decision to invade Iraq to Hitler's invasion of Russia". By taking our eye off the Taliban and placing it on Iraq, it allowed them to form anew. How our actions worried Iran that "they were next", and pushed Iran into defending themselves through striving for nuclear weapons, and keeping Iraq and Afghanistan unstable (to keep us busy and not give us time/material to extend into Iran). How our actions and threats, unfollowed and disregarded when pushed (the use of chemical weapons in Syria would be a "game changer", and then we did nothing) encouraged regimes like Syria to conclude they had nothing to fear from us. How ISIS had evolved their strategies again an again, while we are stuck fighting them with old strategies and failed to adapt. How our timidity in the fight has opened the door to Russia to step-in and take over. How Obama's strategy of "retrenchment" (choosing to "leave" the war instead of ending it) has failed. How we cannot just choose to disengage and avoid the fight because we are tired (isolationist theory), because society today is so interconnected with travel, trade and interaction with the world.
Kilcullen's answer is that the solution is not simple, we have to admit that we messed up (the invasion of Iraq, our addiction to killing terrorist leaders to solve the problem, our withdrawal from Iraq and Afghanistan, opportunism in Libya, and passivity in dealing with Syria), and that until our strategy changes, these disasters will continue.
There is just so, so much information in this book, it will make your head spin. And wonder what in the world we should do, is there even a solution to the problem. Even so, the book is fascinating, extremely well written and documented, and flows very well. I highly encourage you to give it a try.