There are big, big, problems with the 9/11 narrative. I don't know what did happen but I know the standard narrative is a lie. The relationship between the Bin Laden family and the CIA is much too close. 'Some elements knew and allowed it to happen' seems closest to the truth for me at this point.

I don't know if America has a particular interest in destroying Islam, but they may have a general interest in crushing anything that interferes with their economic self-interest and neocolonial ambitions, of which the evidence is vast and convincing. Islam may be the nail that sticks up.
And it isn't compatible with 'freedom' or 'The American Way' either, incidentally, although that doesn't stop us from being butt-buddies with Saudi Arabia, a disgusting regime.

It's America's friendship with vile dictators and its failure to act to stop genocide that really gives lie to its bullshit about freedom and other things in la-la land. American values are for America, and realpolitik is its attitude toward the rest of the world. There is a profound cynicism about international collaberation in the US state department.