The latest on Iran. The Islamic Republic of Iran is the second largest country in the Middle East, with a population of over 83 million, and one of the oldest civilizations in the world. Governed under Islamic theocracy, ultimate authority is vested in Ali Khamenei, the Supreme Leader since 1989. Under Khamenei is President Hassan Rouhani, a position he has held since 2013. Largely considered an authoritarian government, the country has frequently been accused of human rights violations and censorship.