Al Qaeda is the most dangerous terrorist movement in history. Yet most people in the Americas and Europe know very little about it, or their view is clouded by misperceptions and half truths. If the first rule of war is to "know your enemy," then we have a long way to go. This important book fills this gap with a comprehensive analysis of al Qaeda - the origins, leadership, ideology, and strategy of the terrorist network that brought down the Twin Towers and continues to threaten us today.