That one alone pretty much sums it up. You do NOT want to mess with Israel. Period, end of story.
Track record? Look what happened when Israel was threatened by not one but a few countries at once http://encarta.msn.com/encyclopedia_761570433/six-day_war.html
The war described in Ezekiel 38, is future not history: Persia /Iran did not yet attack Israel after its rebirth in "48, as described below.
"""
Ezekiel 38;
4 I will turn you around, put hooks in your jaws and bring you out with your whole army—your horses, your horsemen fully armed, and a great horde with large and small shields, all of them brandishing their swords. 5
Persia, Cush [c] and Put will be with them, all with shields and helmets, 6 also Gomer with all its troops, and Beth Togarmah from the far north with all its troops—the many nations with you.
7 " 'Get ready; be prepared, you and all the hordes gathered about you, and take command of them.
8 After many days you will be called to arms. In future years you will invade a land that has recovered from war, whose people were gathered from many nations to the mountains of Israel, which had long been desolate 8 They had been brought out from the nations, and now all of them live in safety. 9 8....
Sorry i don't want to hijak the thread, just answering what i think about the initial Q:
"What do you think Iran's response would be to an attack by Israel?"