I would add that responding to an embassy attack by launching drones and missiles at a Irael is not very smart either.
It it worth remembering that Iran is Persian, Iran is majority Shiite. The Arabs Sunni muslims do not like Persians and clash with Shitte's on a regular basis. So the chances of the Muslim world uniting are limited and countries like Saudi Arabia are probably quite happy to see Iran get hurt and be weakened.
Iran is playing a very dangerous game, once that could see regime change if they overplay their hand.
