On the morning of September 11, 2001, the entire world was introduced to Al Qaeda and its enigmatic leader, Osama bin Laden. But the organization that changed the face of terrorism forever and unleashed a whirlwind of counterterrorism activity and two major wars had been on the scene long before that eventful morning. In Al Qaeda, the Islamic State, and the Global Jihadist Movement: What Everyone Needs to Know, Daniel L. Byman, an eminent scholar...