Imagine that tomorrow morning a flotilla of space ships appeared in the sky. The aliens aboard the ships declared their intent to kill or enslave every man. They poured into the streets armed to the teeth. They brutally assaulted men, women and children using lasers to decapitate them. They bombed national landmarks. They captured and raped women. Abused and tortured children for sport. Alien leaders demanded that all obey rules they said were handed down by Karful, the lord of Planet Zabane.
What would the response be? All out war? Every American unified in destroying the invading aliens?
Now imagine the aliens went by the name ISIS.