The Shah of Iran was a major reason for why the 1979 Iranian Hostage Crisis came about in the first place. Because the Shah was a dictator and at times a brutal dictator even though he was moderate in other areas like in economic and foreign policy. But he used his vast powers to keep the opposition that was democratic and theocratic down with his Secret Police and arresting people without charges. And holding them indefinitely without trial. And as a result the Islamists in Iran woke up and fought back and took over the country.