The story: Iran has banned the Saudi-produced TV series Mu’awiya, calling it a divisive distortion of Islamic history. The series covers a period known as the “First Fitna [Internal Strife],” which emerged after the killing of Caliph Uthman bin Affan (644–56). Many of the events of that era are perceived drastically differently by Shiite and Sunni Muslims, primarily over leadership of the early Islamic community.

The restrictions in Iran follow a similar ban in Shiite-majority Iraq as well as criticism from Egypt’s top Sunni religious authority. Iranian media and...