I've been struggling for reasoning that extremist left/right-wing (hate) groups would seek to mask itself with the appearance of being linked to Arab-extremists responsible for the 9/11 hijackings.
What would this do? Would they be trying to make us even more pro-Israel? Would they be trying to undermine the country because of bitterness regarding ongoing fossil fuel usage? Are they pro-globalism and need America to 'fall' so that era can be ushered in?
All of the reasons I came up with seemed as thin as the plots of most TV shows. Or as sensible as something heard on Art Bell during a full moon.
Don't see it being left or right, enviro terrorism, or an attempt to gain notoriety by a domestic group.
I would give more credence to a preliminary action from China to play the mid east against us to spread our theater of operations thin.
Read Unrestricted Warfare.