According to Revelation, enemy forces will conquer Jerusalem, and will gloat over it until the miraculous deliverance by The Lord happens. Eventually the conquest will happen, when, I do not know exactly, but when it does, relatively speaking, the time of deliverance and vengeance will not be far off. So yes, the jihadists will have a rather short-lived celebration before it goes south.
There are enough MIRVed SLBMs on ONE submarine to destroy the entire Middle East without launching all the missiles.