Drone Warfare Hasn't Worked
The idea behind drone war was to make war somewhat less inhumane. Instead of responding to acts of war with mass murder, just find and murder the perpetrators. A decade or so of assassinations of "ringleaders" and "masterminds" doesn't seem to have worked though.
I suspect that the failure can be ascribed to our fundamental tribal nature. For most of human history, our security against murder by members of other families or tribes depended on our the members of our tribe, clan, or family being ready to extract revenge. That revenge impulse may well be maximally excited by anonymous assassination from the sky. There is every indication that routine drone assassinations don't discourage future jihadists but recruit them.
The alternative may be a return to the far more brutal methods of the past. If we had had drones during the American Civil War, Lee's army would probably still be in Vicksburg. That war ended only with Sherman's brutal march to the sea, making it clear to the South that further resistance would lead to annihilation.
In Iraq and Afghanistan ISIS and the Taliban have been allowed to operate from refugia, and terror from the skies has not diminished the threat. Half measures in war don't seem to work. We probably need to either give up or go all the way, Sherman style.