Today marks the fifth anniversary of the Madrid train bombings. I was working at CEA at the time, and I happened to be in Paris making a presentation to the OECD that week. It was very disconcerting to be away from home when it happened. Nearly 200 people killed and about 2000 wounded by a terrorist cell inspired by, but not formally linked to, Al Qaeda. That was the sort of viral terrorist act that had me most concerned after 9/11. I thought we were in for a lot more attacks after that.
I haven't seen any reference to this anniversary in the U.S. media, though Google will point you to some. To be perfectly honest, I wouldn't have remembered it myself had I not glanced at a receipt that had 03-11 printed at the top. Go here if you need a refresher on the event.
The biggest puzzle for me in the post 9/11 era is why massive attacks like this have been so rare. For all our problems, the United States is still a very open and prosperous society that takes its freedoms largely for granted. Terrorists could have a field day in our urban centers with just a few suicide bombers. (Put one in the first car and one in the last car on a DC metro train from Rosslyn to Foggy Bottom during the morning rush hour, for example.) What accounts for their lack of desire or ability to strike again, given how effective they were on 9/11 and 3/11? I have no good explanation -- what do you think?