I agree. I was very worried in the first few weeks after 9/11 that there was a second shoe to drop. It never did. IMHO, we have grossly overestimated Al Qaeda's power. If they had a nuke, they would have used it. However, I am still worried about the hijackers' interest in cropdusters. They definitely have or expected to have access to chemical or biological weapons. I hope our guys massing in the Middle East for the attack on Iraq have good anti-aircraft defenses, especially against simple small planes.
We've been lucky in the sense that Bin Laden had no strategic vision. Immediately after 9/11, a series of follow up attacks would have sent our economy into chaos and depression.