"We believe that the worst thieves in the world today and the worst terrorists are the Americans," Osama bin Laden told a CNN reporter three years before 9/11. "Nothing could stop you except perhaps retaliation in kind. We do not have to differentiate between military and civilian. As far as we are concerned, they are all targets."

On 9/11, two of the four targets were purely civilian. Last week in Russia, Islamic terrorists took this cowardly approach to even baser extremes, going after children on the first day of school. We should be horrified, but not surprised, when terrorists do what they say they are going to do.

Killing other Muslims seems a more controversial tactic among terrorists, particularly the captured murderers of school children in Russia who seemed shocked that their leaders killed other terrorists. In deed as well as in word, bin Laden has been clear where he stands on killing other Muslims: "when it becomes apparent that it would be impossible to repel these Americans without assaulting them, even if this involved the killing of Muslims, this is permissible under Islam."

First and foremost, terrorists are rationalizers. They justify their barbarism with certitude in the nobility of their cause. Killing other Muslims, Western civilians, and even school kids is thereby rationalized. Calls to understand why the terrorists attack us imply that there's some way to identify and correct our problem, and thus satisfy extremists who murder adolescent children. Solving the terrorist problem, however, involves a greater focus on killing the terrorists rather than understanding the terrorists. The latter course assumes that the terrorists will react rationally to change while the former course assumes that the terrorists will act like terrorists.