More than a year ago my monday-morning quarterback guess was that 9-11 was a tar baby strategy on the part of al Qaeda: that the idea was that we would either be too weak willed to respond at all, or if we responded we would overcommit and end up in a Soviets-in-Afghanistan style war of attrition that we cannot win.
A year or so later, I haven't seen any reason to change that view. It seems to me that al Qaeda's strategy - if that was the strategy - worked. The reason we haven't been attacked again is because things are going exactly according to plan. Instead of narrowly focusing on wiping out al Qaeda and getting serious about preventing the form of sedition called "Jihad" at home, we decided to change the world one predominantly Muslim country at a time, starting with one that had nothing to do with 9-11.
And if we don't want to have various parts of our anatomy handed to us over the long run, one of the first things to do is admit and understand why we've had a certain one handed to us in the short run.