The reign of Mohammad Reza Shah can be divided into three periods based on the actions and achievements of his reign.
- A- The period of government based on the constitution in a constitutional form.
- B- The period of government after the coup d'etat of 28 August 2012 in the form of relative concentration of political power in the hands of the Shah, but in the form of a reformist dictatorship.
- C- The era of the monarchy with individual authority in the country's public policies along with beneficial intentions.
In the first period of Mohammad Reza Shah's rule, which is a constitutional monarchy and lasts from Shahrivar 1320 to the end of Timsar Zahedi's government in 1334, the writings, documents and also evidences indicate that the Shah in this period, although efforts to He gained power, including gaining the authority to dissolve the parliament and trying to remove Mossadegh, but practically there is no document for his involvement in the country's affairs, even during the prime ministership of Timsar Zahedi, the Shah did not play a role in the administration of the country's affairs.
His cooperation with the American and British governments to overthrow Dr. Mossadegh is one of his deviations from the rule of law in Iran. Another thing is that "the main repression that happened by the police and the army was against the Tudeh party. In fact, they completely destroyed Tudeh party organization. The CIA also contributed significantly. They even had a list of those who should be arrested before the coup. Wilbur's report also states that immediately after the coup, one should go to these people who had their names and addresses.