Until the attacks of September 11, 2001, few Americans knew anything about Islam, let alone about the distinctions between Sunni and Shi'a, the Sufi and Wahhabi, the origins of the Holy Qur'an and Shari'a law, and the respect that all Muslims, even secular ones, harbor for the prophet Muhammad, his family, and Islamic traditions. In The Sunni-Shi'a Divide Robert Betts traces the tortuous history of Islam's sectarian divisions, emphasizing the most important one, the Shi'a departure from Sunni -orthodoxy.- Although the majority of Muslims remain faithful to the Sunni sect of Islam,...