NPR has a very interesting piece on the Shia-Sunni split.
The division in Islam between the Shia minority and the Sunni majority seems to be deepening, not just in Iran and Iraq, but across the Middle East. The split occurred soon after the death of the Prophet Muhammad, nearly 1,400 years ago.
Catch up on your Ismlamic history and find out why Shiites are looking for a coming messiah.