There's another theory that Saudi Arabia funded the attacks. Regardless, the media and the government pounced on "Osama bin Laden and those naughty Afghanis did it!" way too quickly, like 2 hours after the second plane hit.
1. Bin Laden was not Afghani
2. al Qaeda is/was not Afghani
3. The guys who perpetrated the 9/11 attacks were not Afghani (Mohammed Atta was Egyptian)
4. The Taliban actually hated al Qaeda for bringing foreign attention (and ultimately intervention) into Afghanistan.
5. Counter terrorism and intelligence forces throughout the globe were well aware of the position of AQ in Taliban held regions in Afghanistan as a result of 4. Also really helped when AQ claimed responsibility for the 9/11 attacks.
Oh...it's this thread again...Fuck.