The horrific and spectacular acts of violence committed by the Islamic State of Iraq and Syria have shocked the world.Mass executions of innocent people, the beheading of captured journalists, the intentional attempts to inflame sectarian tensions, widespread sexual violence, and many other human rights abuses have quickly identified Islamic State as a brutal and ruthless actor.

The language used by our leaders to describe and respond to the horrors of Islamic State has been unsurprisingly forceful. Tony Abbott, the Australian Prime Minister, has referred to the group as an "apocalyptic death cult" whose aim is to "have heads on stakes."

U.S. President Barack Obama conveyed a similar message in his recent speech at the United Nations: "There can be no reasoning — no negotiation — with this brand of evil. The only language understood by killers like this is the language of force. So the United States will work with a broad coalition to dismantle this network of death."