"You can't fight ideas with bullets."
-- NSF Commander, Liberty Island mission, Deus Ex
You wouldn't expect to find meaningful political commentary in a computer game, but Deus Ex was not a normal computer game. This simple but irrefutable truth sums up for me why a 'war on terrorism' is a fool's errand. You might as well try to declare war on vague feelings of despair. An idea can only be challenged with a better idea.
You can if you shoot people through the brain. That works.
Ideas aren't usually that contained.
You have to be quick. You have to quarantine it, like flu, before it spreads, like cancer.