Actually, that is EXACTLY what we should have done. The Shah murdered tens of thousands of Iranians, tortured people, oppressed people, squandered the wealth of the country on lavish palaces and celebrations for himself. He actually needed to answer to his own people for his crimes.
Instead, we took him in, and Iranians had a legitimate fear we were going to do what we did in 1953- put the guy back into power by force.
It wasn't Trump's money to give. We were returning assets that rightfully belonged to Iran. Iran also returned assets that rightfully belonged to the west. The idea is to normalize relations, not isolate Iran and drive it into a camp with Russia and China.
The only country that ever used a nuke was our own. Against a country that had already been defeated and was desperately seeking a peaceful settlement.
The point was, the Iran treaty had inspectors on site verifying Iran was not building nukes. Trump tanked that deal, and frankly, if I were Iran's leaders, I would be making a nuke right now.