This short film, summarising the key points from last year's report by think tank Demos on combating terrorism (The Edge of Violence), is worth a view.
Their key conclusion: that most terrorist recruits are non-religious young men (who remain superficial 'converts' at best...rarely getting beyond parroting general [and often un-Muslim] platitudes), with few opportunities in life, who are initially attracted by the simple promise of fun, excitement and 'cool' (you can play with guns!).
Which is a classic 'change behaviour' strategy: get people behaving in a certain way and their beliefs will follow on.
And in light of this, Demos ask whether the best way to undermine this recruitment strategy is, well basically, to take piss and make terrorism uncool.
Which, interestingly enough, is pretty much the same approach we took here at QS with some work we did for Crimestoppers a few years ago, aimed at kids on the edge of criminality.