I think we have to come to the realization that its going to be a two front war. One is classic bombing, like this, and use of cruise missiles and what not, to attack them when we can find them, especially leadership.
At the same time, we have to win the longer term, much less tangible war, of keeping them from converting people to their cause, and prevent them from inspiring the lone wolf types to act for them.
The hard part, of course, is going to be keeping the former from undermining the latter. There's no easy answer on that, its shades of grey, and I guess at some point we have to trust that the people making those tactical decisions have both in mind, as they pick and choose their actions.