Prageru: What does ISIS want?

This question can be answered, but first this one has to be. How was ISIS created? ISIS was formed from a group of Al Qaeda members who relocated to Iraq. After Iraq fell, ISIS quickly took advantage of the power vacuum to spread it's power. It even established small provinces all over the world. These are small, but commit terrible acts of terror all the same. ISIS portrays itself as muslims fighting a continued Crusade, and want to form a new Caliphate in the eastern continents. HOw to defeat them? Take down their territory in Iraq and Syria, and their Caliphate claim will go void, undermining many muslims allegiance and support.