The aim of terrorism is to make the target terrorise themselves with draconian changes to their lives, QED airports this week. 911 used up hijacking as a viable weapon of terror but we still can't take a pair of nail clippers on to a plane. We do the terror to ourselves, the effect of the initial bombs etc is tiny compared to what we do to ourselves. That's why civilians are targeted. Politicians react to public opinion so they take measures that they think the public want, not necessarily useful.