The agenda of fear and hate driving conservative candidates for president today is the last thing we should do. So what to do, instead. There's Duncan Black on one side saying, do less blowing up. Kind of vague, but not meaningless. Josh Marshall on the other hand says do more blowing up of ISIS (also stop blowing up Assad, but the main thing is blow up ISIS).
I'm somewhere in between but think I'd lean more towards the pretentious one's argument. Many people have reminded Republicans that it was their invasion of Iraq that put us in this fine mess. Less remarked is that ISIS talked a big game in the caliphate's first year, but pretty much concentrated on local genocide, rape, and enslavement - we were blowing them up first before they got to Paris. Maybe people don't make this argument because of the whole genocide thing - the pretentious Duncan sure glosses over that.
I'm no expert but I read history, and in World War II neither side liked getting bombed, making efforts to retaliate more for domestic consumption than out of real strategy. From the Doolittle Raid to the V-2, the motivation basically was to strike back.
Duncan's right that blowing up ISIS creates problems, although not blowing them up in some situations allows them to create genocide. So I'd say do more blowing up when needed to stop genocide despite the risk of retaliation, but getting rid of ISIS where it has some popular support isn't our job. Especially in Iraq, the campaign in Anbar province might be going too well - the Iraqi Shiite government is succeeding in taking over Sunni areas without real Sunni participation. That sounds like a recipe for future problems, and not where the rest of the world needs to tread.
Syria is a bit different, Sunnis are fighting both ISIS and Assad. I once favored a safe zone in the northwest, assuming Turkey's government would be less-than-evil about who got through. I don't know if that could still happen - maybe. Containing ISIS while locals figure out how to handle them seems like a better approach, and it would mean less bombing than we're doing now. Maybe that would work, like Duncan says. Working with Assad would be a huge mistake and again not where the rest of the world needs to tread.
Paris was a tragedy. There are many other tragedies. Let's make things better instead of worse.