That seems consistent with my original argument that terrorism is essentially the same type of phenomenon as street gangsterism - an exercise of wanton violence to prove one's virility and toughness to other males in the pack. The political ideology attached to it - left, right, Islamist, Communist, national liberation etc. - is a mere window dressing created by sympathizers and supporters. Treating that ideology as a motive of the behavior in question is hopelessly misguided.
Which brings us back to the question of motives. I agree with Doug that the police cannot stop all acts of terrorism, and that understanding the motives is important for prevention. However, I also believe that the motives of the actions in question are rooted not in ideology and politics, but rather in the dysfunctional male psyche - its reliance on subjugation/domination collective arrangements (sports teams, the military, corporate hierarchies, and of course street gangs) and wanton aggression to define itself. As such I do not think it can be prevented, or at least not by civilized means. The best we can hope for is to identify the affected individuals and confine them to social circumstances where their aggression can find alternative, less destructive, expressions.
Wojtek