Same theme as the rabid dog. The DWB and WHO didn't try to negotiate with Ebola viruses - they didn't arrest them or give them a fair trial or try to negotiate nor attempt any rehabilitation nor appeasement. They simply exterminated the deadly menace without mercy.
What is needed both militarily and as a civilian mindset is a concerted effort by Europe Russia Oz and the US to eradicate Daesh leaders and blast away at the ranks (whether refilled with fresh recruits or not) until there are no more ranks to blast away at. A white flag from an outgunned Daesh squad should be regarded as an upcoming target practice session. No POW Conventions, no bull**** EU Courts, no "UN rights", no nothing. It'll take a while - but your average dumb uneducated radical loonies will eventually cotton on that joining Daesh or Al Craeppa will lead to 100% certain death in a very very short time.
I admit though the biggest weakness in the West is these miserable bleeding heart Human Rights groups who unfortunately have considerable political power. These groups, like pacifists, are eventually silenced once blood is spilled on their own soil, but thousands of innocents have to be slaughtered first before they're finally shut the f****d up.
Also...I object to these murdering Daesh thugs being called "fighters" - they are gutless yellow-bellied subhuman maniacs utilising a weapon of war called religion to achieve obvious political aims.
Nuff said on my part.