I don't think that if Israel wipes out Iran's nuclear bombing capability that it would unite the Arab world against Israel; that is, not enough for an all-out attack on Israel. On the contrary, I believe that most Arab countries would be pleased with Israel's action.
The whole thing frightens me to death, quite frankly. But I see no way out for Israel. A second Holocaust is bound to happen if that madman Ahmadinejahd has nukes at his disposal.