If the US knew what it was doing, 9/11 would never have happened. The situation would never have existed.

I don't think that is a fair comment. It assumes that somehow the current Israel - Arab situation has some obvious easy answer that American leaders (and everyone else) has missed.

It assumes that Arab fundamentalism is directly due to US actions. While US actions undoubtedly have aggravated it, the underlying religious movements have fairly complex bases.

I could go on. But that seems a hopelessly naive position.

To me what is surprising is not that 9/11 happened but that it didn't happen until 2001. I think the US has been very lucky.