1. Has regime change ever been achieved from the air alone?
2. Is there an organised pro- American opposition in Iran ready to take the place of the current regime.
If either of the answers to these questions is no, it seems likely a lot of people will die needlessly and there will be far reaching effects on international trade for no definable benefit.
Alternatively, Trump could just get bored, claim a victory and call it all off at some point with little to show for it apart from the butcher’s bill.