ISIS is ten miles wide and an inch deep. They can’t repel a coordinated counter assault on them. Once their heavy equipment is destroyed they’ll be reduced to an insurgent force.
They've got to got kick the ant pile then go to work.
It depends on how much local support they receive. You don’t destroy insurgencies via air power alone. And exactly who will lead the counter assault?
Yep. Hence their need for terror.
No supply lines and troops way over extended. They only got what they can carry off.
Now if they can somehow take Bagdad then the Game changes.