Why hasn't Al-Qaeda attacked the US again?

Slate's Timothy Noah published an absolutely incredible article trying to reason out exactly why we haven't been attacked again by Al-Qaeda. In it, he smartly avoids trying to pinpoint the exact reason, rather preferring to lay out each of seven competing theories, and arranging them on a scale of most comforting to most worrying. My favorite is the "Flypaper Theory." FTA (taken from an interview by Lt. Gen. Ricardo Sanchez)

This is what I would call a terrorist magnet, where America, being present here in Iraq, creates a target of opportunity, if you will. But this is exactly where we want to fight them. We want to fight them here. We prepared for them, and this will prevent the American people from having to go through their attacks back in the United States [italics mine].

While perhaps less plausible than some of the others, the idea really intrigues me. He's spot on in his arrangement- terrorists-are-dumb really is much more comforting than they just haven't gotten around to it yet.

This article is really long, but absolutely worth a read. Check it out and let me know what you think.

Link for those who missed it earlier- via Slate