The story of post WWII Iran is a lot more complicated than the Shah of Iran Iron Hand dictatorship and the Ayattolah's one thereafter.
It had started on the way to full independence from foreign imperialism, and, under Mohamed Rheza was on its way to possibly be the first successful Constitutional Monarchy and modern state in the Middle-East. But the Americans (with good support from the Brits, I regret to say, and especially one called Churchill) couldn't keep their friking fingers out - because oil - and US company not being the ones making the insane profits anymore - but the money going rather to the people of Iran.
If the US hadn't interfered (by fomenting a military coup d'etat and turning the Shah into an absolute power - dictator - under their control) when Prime Minister Mosadegh nationalized British oil and if the Shah had then supported his PM, who had the backing of the assembly, you might have had a fully modern and non-religious, democratic society in Iran today (remember, they are Aryans, not Arabs) on par with Israel or better.
So if the Shah's son return, as Shah of Iran, I hope that if Crown Prince Reza returns and is anointed by the people, he will see fit to go back to the way things were under his father before he was turned into a dictator, and will recreate a constitutional order such that he would rule as a constitutional monarch.
If that happens, watch the Iranian people's pent up energy in all fields of human endeavour explode like there is no tomorrow.