to limit the power of the shah but had "never suggested he was in favor of abolishing the constitutional monarchy," saw these attacks as a challenge, as removing the shah would violate the constitution. The next day his regime ordered the military into the streets, and "up to 600 mid and low-level Tudeh activists were arrested in Tehran alone." With its network "severely damaging" the party reversed course once again, and "ordered a demobilization" of its preparations to fight a coup. Taking advantage of the quiet, the CIA and its Iranian allies struck again, and on 19 August the coup d'état replaced Mosaddeq with Zahedi. The coup was a major event in Third World and 20th Century history and there is debate as to how much of the blame for the overthrow can be traced to bribes paid by the CIA and how much to domestic dissatisfaction with Mossadeq. Whatever the motivations, Mohammad Reza Pahlavi thereafter assumed dictatorial powers and banned most political groups, including Mossadegh's National Front, which along with the Tudeh Party, continued to function underground. Crackdown following coup The mass arrests, destruction of its organization and execution of some 40–50 leaders following the coup has been said to have "destroyed" the Tudeh. Between 1953 and 1957, Iranian security forces using "brute force, together with the breaking of the cryptographic code – probably with CIA know-how – … tracked down 4,121 party members." This constituted the whole Tudeh underground and "more than half the party membership". Tudeh infiltration of the military by the TPMO totaled 477 members in the armed forces, "22 colonels, 69 majors, 100 captains, 193 lieutenants, 19 noncommissioned officers, and 63 military cadets." Ervand Abrahamian notes that none of these was in the "crucial tank divisions around Tehran" that could have been used for a coup d'état and which the Shah had screened carefully. "Ironically, a Tudeh colonel had been in charge of the Shah's personal security – as well as that of Vice President Richard Nixon when he visited Iran. The Tudeh had the opportunity to assassinate the Shah and the U.S. vice president but not to launch a coup." Maziar Behrooz is more optimistic about the party's chances of stopping the coup, saying that while "most of the Tudeh officers were in non-combat posts," they "were in a position to access and distribute weapons. In their memoirs, TPMO high- and middle-ranking members have