Ayman al-Zawahiri leaves behind a robust network of strategically aligned but tactically independent al-Qaeda affiliates operating in Africa, Asia, and the Middle East.

The Shia Revival offers an in-depth analysis of the various causes and forces that have contributed to this long-born political struggle for the soul of Islam and sheds light on historic moments of S…

As sectarian tensions convulse Syria and Iraq, the Council on Foreign Relations has released a new interactive guide examining the roots and consequences of the divide between Sunni and Shia Muslims.