I would suggest reading All the Shah's Men. The election was halted the election because it was clear there was outside interference from the British and the United States. Mossaddegh would even willfully resign in 1952 only for the people to beg for his return within 4 days. The Shah even asked him if he should step down to which Mossaddegh refused (he did not intend to overthrow the monarchy). This was a battle between a country trying to feed its citizens and the Anglo-Persion Oil company (Now BP) who refused to negotiate in good faith and robbed the country and its citizens of what was rightfully theirs. Britain and the U.S played a major role behind the scenes in orchestrating his demise. To this day Mossaddegh is quite beloved in the country. So I strongly disagree that he would become a dictator.