Most of the time when you kill the top two leaders nobody wants to be the third leader.
It seems these "leaders" are on Obama's "goodbye" list from Lebanon to Pakistan and he's likely to be doing air strikes 24/7/365.
Or drones or cruise missiles.
Now that the ISIS Caliphate is minus it's first Caliph who will be the next Caliph?
As long as war against humanity is war against the United States, we might as well kill these folks with abandon.