Given ISIS' insistence that its view of Islam is the only correct view, it doesn't seem likely ISIS will accept anything less than a total victory in Iraq, Syria, and neighboring countries. So the calls for Iraq to be fairer to the Sunnis and end sectarianism don't seem like they will solve anything. ISIS wants to retake the geographic territory it views as having been stolen from them by the West (Britain and France in particular) a century ago, and as to religion, it's their way or the highway (with the highway being a graveyard.)
While ISIS opposes the policies of the U.S. Government and many in Europe, it doesn't seem to be at all focused on putting its flags down here. ISIS seems intent on dominating its own territory. While its recruitment efforts are aimed at Muslims in all parts of the world, it want the recruits to come to where ISIS is fighting and strategizing, not start new wars in their home countries.
ISIS is intent on destroying those who oppose or stand in the way of its goal of creating a unified Islamic state, in which its view of Islam controls the government and every facet of the lives of the people. It doesn't seem interested in turning non-Muslim dominated Western countries into Muslim states. ISIS has more in common with a military organization rather than a terrorist one. After all, all wars are violent and end in death and atrocities.
The West calls ISIS terrorists. Muslims who oppose them call them Kharjites, a name for a group of violent rebels and outcasts that existed centuries ago, which had a different view of Islam and wanted to impose it on others. I think they are militants (fighters) and religious fanatics (or perhaps just purists) who want to overthrow the governments of existing Islamic countries and install their own governing systems. It's really a war over territory and ideology.
ISIS has been on a big roll for over a week. It's waging war in several places, and winning in all of them. It doesn't seem they leave much to chance, but instead, like any successful war machine, strategize, plan and map out their battles, recruit and train their troops, keep up morale, conduct a PR campaign, and soldier on.
It really has very little to do with us, and we should stay out of it. It's long past time we stopped trying to impose our view of how countries should be governed on countries and people on the other side of the world.