I think trying to wipe them out will only have us enter a long, costly war with them, which will end not because it is won, but because of war-weariness. They'll just have an even easier time to recruit new members, with us being seen as aggressors. I think the tough but correct way of dealing with them is to work towards reducing social class differences and poverty. ISIS, like many extremist movements, largely plays on emotions as they recruit members. Emotions like anger, despair, frustration, neglect.