If the Iranian leaders still do survive and the government does not fall, we can sign a cease fire with no fly zone over certain parts of Iran.
I think if we decimate their nukes and military infrastructure, say, in a month or two of an air war, the regime will be taken over by left-over military who, together with the people, didn't want to be humiliated and broke over Iraq and the nuke madness. At least, that's what I hope.
If the regime survives intact, it will have a rough time keeping order and the assassinations will take a heavy toll on them.