You're right. But one can't be amazed how little we've learned from our history. Freedom, my friend, has many enemies. But ultimately, Freedom always prevails. ISIS will end up on the shitheap like the Nazis, Communists, Khmer Rogue....but the ISIS plague will probably engulf the entire Middle East before they are wiped out.
The shia won't allow it to happen..... Iran is already directly involved in the fight against them. Best case scenario is they fight amongst themselves for the next few years, and forget about the rest of the world.