And if ISIS wins, we get another government that answers to a different murderous mullah and hates the U.S. Either way, we lose.
So why should we be involved in a situation in which we lose either way? The only way to “win” is to make sure their fight drags out for a long time.
If Iran gets too strong, new terrorists will swarm in to support ISIS.
No, because whomever comes out on top will renew focus on the Great Satan. They will not destroy each other for our benefit.