With Iran's leadership reeling from attacks from American and Israeli troops, Reza Pahlavi is arguing that he is best positioned to take over the country in the aftermath of war. Pahlavi, the oldest son of Iran's last shah, is a longtime political activist living in exile in the U.S. On Sunday, he told Fox News' Maria Bartiromo that he has the support and mandate necessary to helm a transitional government in Iran, after the killing of Iranian Supreme Leader Ayatollah Ali Khamenei on Saturday.