Leaving aside the utter futility of grading terrorist organisations by their actions - it seems you score points for warnings, lose them for beheadings ...
I also believe that negotiation has to be attempted with ISIS, and it has with all foes throughout the ages.
The current battle lines between ISIS and the West are going nowhere.
This is an enemy that cannot be fought with standard armaments, either in terms of beating them into submission, or changing their mind-set against the West.
I believe that ISIS are relatively a very small group, and with dialogue not just with them, but with the wider communities on which they must rely in order to function, we can start to move forward in terms of sorting out where we go from here.
Simply sitting with our arms folded and our mouths clamped shut is going to continue things through this century and into the next.
Saying 'We don't negotiate with terrorists ... ' is a stubborn futile arrogant position to take, and it panders only to a mis-aligned sense of self-righteousness that sees us entrenched in this war of attrition which takes its toll on a daily basis.
We can sit on our mountain firing missiles at theirs, and getting missiles back, from now until doomsday, or we can try another tack, since that has failed, and continue to try and promote dialogue.
I know that gainsayers will trumpet the usual nonsense - 'They want to destroy us not talk to us ...' which may well be true, but unless we try, we carry on as we are, which is nowhere.
If we present ourselves, those wiling to hear (and they may just be out there) will understand that we are not corrupt and intent on destroying the Muslim faith - and that similarly, trying to take over the globe for Islam is utterly unrealistic, and co-existence is the best option any of us are going to get.
By dialogue, we can explore or differences, and more importantly, our similarities, and see if there is a way forward. It has to be worth trying, and trying hard - nothing else is working.