Wow, Blackadder, really?!
I don't have to explain or justify where my loyalties lie, ymb. However, I think helping such people not only helps them, but also the rest of us. Nor am I really playing roulette with people's lives either -- at least, no more than you are, in some sense, because you still have the problem of the misguided whose lives you seem happy to discard as no longer worth trying to improve. And the knock-on consequence is that, again, the root problems remain. You will still have young people, disillusioned with "the West", running away to join Jihad or what-have-you. Not all of them will even run away, some will stay here, and we have seen what they can do. I can't see this problem going away by some sort of crass numerical argument that once "over there" there are fewer here. It has to be tackled actively, by working with those who may wish to run away in the future, and with those who already have but since changed their minds.
Doing neither of these, or doing only one of them, is certainly as dangerous as trying to tackle the problem, and frankly is more so.