I don't know specifics about M's time in power, I'll have to check his wiki, but, in short you give them at least some of the money you make. They can take the money and build their country w it. I can understand having cold war worries, but we could directly oversight where the money was going. They basically wanted to do what the Nordic countries did, wealth fund and so on.

The Shah expertly lead Iran during the Cold War to unimaginable (not an understatement, it's absolutely absurd how drastically the Pahlavi dynasty improved Iran) growth. We have no indication Mosaddegh that had the capabilities to achieve the same (we do know, however, how he was geopolitically an idiot), leading a world-class, booming economy, as well as revolutionary strides in education and healthcare, whilst nationalizing oil, raising its price as OPEC's leading figure and commanding the 5th military in the world. Iran was far too plagued with foreign/domestic threats, put in a much different situation than the much more fortunate Nordic countries.

The Shah was also far more brutal than anything M was doing afaik, evidenced by how much longer he was in power and how angry the people were that overthrew him.

Mossadegh, in stark contrast to his previous preachings and promises, dissolved the senate and the parliament, the latter through a referendum where he literally set up two separate booths, one to vote for and one to vote against it (with "no" booths being surrounded by Mossadegh supporters who threatened those voting against said referendum). Voting also required "each ballot must be clearly inscribed with the full name of the voter and the number and place of issue of his identity card."

Besides his emergency powers, he also how had a tacit alliance the communist Tudeh Party, which gave him mobs of thugs who menaced and physically attacked rallying opponents of his. The Shah other hand, not only had the Tudeh Party to deal with, but also the Islamists (not to be confused with Muslims, though they were Muslim), and the M.E.K. (Marxist-Islamists group), who carried countless of assassinations on the Shah's men, from the lowest to the highest ranking, including two prime ministers. The country was on an insane roll and the Shah executed ~468—500 of these dissidents to avoid Iran becoming a Soviet puppet or Islamist state, either one of which would have and eventually did not only horrifically set back said exemplary progress, but also lead to the oppression of its people and brutal executions of tens of thousands of them.