This examination of al-Qaeda's decline since the 9/11 attacks focuses on the terror organization's mutation and fragmentation. It looks at its partnership with the local and regional jihadist networks that played a pivotal role in the Madrid, London, and Fort Hood attacks, arguing that, although initially successful, such alliances actually unraveled following both anti-terror policies and a growing rejection of violent jihadism in the Muslim world.

Challenging conventional theories about al-Qaeda and homegrown terrorism, the book claims that jihadist attacks are now organized by...