I've been wondering this, too

Via Althouse:

Here's what really gets me about the 9/11 conspiracy theory. How can anyone believe it now? Of course, it was always completely crazy, but some people believed it anyway because they imagined a hyper-organized, hyper-competent, hyper-secret Executive Branch. Now, you've watched all these years of struggling through the Iraq war. How can you cling to the premise that the Executive Branch is hyper-organized, hyper-competent, hyper-secret? Do they think Bush and Cheney deliberately conducted the war to give it the appearance of a big screw up in order to throw us off the track?

If 9/11 really had been an inside job, we'd have found great big piles of ready-to-use WMD and a nearly-ready nuclear weapons program six months into the war.