I read a very good article on Wired the other day about the way our brains interpret acts of terrorism and how the more hideous and terrible the act of terrorism is, the less likely the terrorists are to get their way, however modest their goals actually are.  It’s a decent read without being to scientific, here’s the gist:

 “In other words, terrorism doesn’t work, because it makes people less likely to acquiesce to the terrorists’ demands, no matter how limited they might be. The reaction to terrorism has an effect completely opposite to what the terrorists want; people simply don’t believe those limited demands are the actual demands. “

People are less likely to believe that terrorists will really be appeased if their demands are met if the terrorists do something horrendous to the population at large (e.g. 9/11).  I think that this whole idea probably rings true for most of us, really.