The thread onto which I intended to post this is now locked, so I’ll post it here.
Read this:

It’s central thesis (not one I quite agree with) is that 9/11 (and similarly, the 1998 Embassy Bombings) were a blowback from a lengthy and complex relationship between militant Islamist groups and Western intelligence and security services. Ahmed centres the book around an agreement struck between the CIA and Ayman Zawahiri regarding operations in the Balkans, which involved a similar logic to the ‘covenant of security’. Under the former, as long as Zawahiri played the part the CIA desired in the Balkans conflict, they ignored his activities elsewhere. Under the latter, Britain granted asylum to and subsequently protected various ‘Al Qaeda’ luminaries, including Abu Hamza, Omar Bakri, Haroon Aswad (supposed mastermind behind the London Bombings in 2005) and Anas Al-Liby (who was apparently involved in the 1998 Embassy bombings).
Well worth the time of anyone looking for an alternative to military-industrial propaganda and conspiracy theories.