I want to caution people about thinking that somehow massive force will solve this. It won't. Part of the problem with Daesh is that it runs on an idea. You can't kill an idea with military force. (Do I need to start pulling historical examples, or are all of you smart enough to think of a few on your own?) Part of the problem is that Daesh provides civil and quasi-governmental services to the people under its protection in areas it controls, not unlike what the Taliban does in parts of Afghanistan and Pakistan (where the respective national governments have failed or left a power vacuum). Dealing with that is also tricky, because one of Daesh's strong areas is in Syria, which has been ripped apart by civil war, and before that, had a dysfunctional and autocratic dictatorship which overwhelmingly concentrated its service-provision to the large cities and Assad family tribal strongholds, leaving much of the rest of the country without any real benefits of government to speak of. (An ex-client of mine used to do civil society promotion and NGO support in Syria. I'm certain he was here in Canada because the Assads, who didn't like non-Assad-patronized NGOs, wanted to have him imprisoned. He said that a dozen of his colleagues had already been to prison, and if the words "Syrian prison" don't make you shudder a little, you lack imagination.)
I hesitate to advocate the sort of normal conflict resolution or peacekeeping military intervention for this, as it seems to me like in this case that it would be akin to picking sides in a civil war, and I can't see how the Assads wouldn't benefit from it, and I like them almost as little as I like Daesh. I'm also not sure of the bonafides of most of the anti-Assad rebels, since they may be just Daesh in their Friday clothes. I also can't help but surmise that the western world kind of left Syria to twist in the wind a little bit after the fall of the Soviet Union, given that Syria was explicitly "socialist" in the manner of a Soviet client state, which it had been, and I can't imagine that losing its powerful backer and not getting any help improved the situation there, either.
So. Trace back and cut off the flow of arms and money to these people. Freeze their bank accounts. Dismantle their financial infrastructure. Arrest their money-handlers. Arrest their major individual donors. Fuck, for all I care, send the Mossad after them for a nice quick clean assassination or several. Yeah, it's not technically legal, but it does work (viz. Black September), and the Israelis certainly aren't above a little terrorist-killing wetwork. Find out if Daesh has state sponsors, and shut the pipeline down. If there's a Saudi connection, for the love of G-d, isn't it about time to go after them too?
Obviously, what is happening right now isn't working, and doing more of the same will work even less. I think the French and the Lebanese would be smart to enlist as much anti-Daesh international cooperation as they can get (not unlike all the help that was offered to the US post-9/11...and squandered), and use it productively. Bombing Syria even further back into the Stone Age won't help, even if it will make some people feel better...and radicalise more Syrians.
In other news, friends of mine in Israel buried their neighbours today, thanks to yet another Palestinian ambush.