I can see the point of regime change if Iran did this as it would prevent another attack and also let the rest of the worlds leadership know they will be removed from power if they do something.
Yeah right, because that has worked so well in the past.
Turns out the world unites against you if you try that. We just tried eight years of that policy.
I was totally for it, mind you. But there are just too many people world-wide, including in the west, who will do absolutely anything in their power to protect such tyrants.
I'm not sure dropping a nuke would have the same affect if the people in power survived. It would also turn the vast majority of the world against the US as it is punishing the people of Iran not the government of Iran.
Can you name an example of the world turning against a country because of its brutality?
History has shown that useless and exaggerated violence is the way to go if you want international support. But try doing only what's necessary and the world unites against you.
If a major attack happens in America and America kills tens of thousands because of it, the war will be OVER and nobody else will have to die. Nobody will speak up against a country that reacts like that.
I don't like it any more than you do, but the rational remove-the-dictator-from-power just isn't as accepted by the "international community" as the trick with the genocidal violence.
Note that for example Al-Bashir, the genocidal tyrant of Sudan is a respected leader in the Muslim world. And very few "peace activists" in the west bother to organise huge demonstrations against the genocide in Darfur. But they do organise huge demonstrations against your "regime change" proposal.
What you are talking about is indeed the best way to settle these issues. But "peace activists" and progressives have made it utterly impossible and the "international community" always condemns those who try to respect the rights of people and rewards and respects those who don't.