Both Pahlevi Shahs were the right men at the right time. Reza Pahlevi (1925-41) catapulted Iran from the medieval Islamic world into the 20th century and fought Sharia and the Islamic Clergy at every turn. His son directed Iran on a western, pro-American way. He was an ally of Israel and in his own words the only stronghold in the Middle East against Communism and Islamism.
Thank you Jimmy Carter for betraying him in favour of the Ayatollah!
The Shah of Iran built on what his father had started, and what the Allies are trying to do now. A balance. Iran under the Shah had balance and the benefits of both modern society and an understanding of the requirements of Islam.
The SAVAK was much more about Islam than western mores.