Osama bin Laden has been replaced by ISIS in today's headlines. And although the Iraqi branch of al-Qaeda was the precursor to the Islamic State of Iraq and Syria (ISIS, formed in 2013) – also known as the Islamic State of Iraq and the Levant (ISIL), Daesh (an Arabic acronym), or simply the Islamic State (IS) – the dissimilarities between ISIS and al-Qaeda central are profound. For example, ISIS, which was disowned by al-Qaeda under the leadership of Ayman al-Zawahiri, has attempted to establish a caliphal state apparatus; while bin Laden's al-Qaeda generally eschewed videotaped executions (instead opting for sensational terrorist attacks), ISIS, for some time at least, seemed to be using videotaped executions to entice potential recruits and project an aura of strength; and while the “face” of al-Qaeda, bin Laden, recorded and published numerous statements, the self-proclaimed caliph of ISIS, known as Abu Bakr al-Baghdadi (né Ibrahim Awwad Ibrahim al-Badri), has, as of this writing, been quieter.

Born in 1971 in the Iraqi city of Samarra, al-Baghdadi was raised in a lower-middle-class farming family. He earned a PhD in Islamic studies in 2007 from a university in Baghdad established by Saddam Hussein. (Both his master's thesis and doctoral dissertation were on the subject of Qur'anic recitation, not Islamic law.) His path to a doctorate, however, was complicated. In February 2004, he was detained by American forces and held for roughly ten months after visiting a friend who was wanted by the United States. Following his release, al-Baghdadi's move toward radicalism became more obvious: he joined al-Qaeda in 2006 and, later that year, was assigned the task of overseeing the implementation of Islamic law in the newly formed, al-Qaeda-affiliated Islamic State of Iraq (ISI). He became the leader of ISI in 2010 and then ISIS when it was established three years later. In 2014, he declared himself caliph of the world's lone “Islamic state.”

In the eyes of those who recognize al-Baghdadi's authority, he is in a position to sanction and call for aggressive jihad. (All indications suggest that the overwhelming majority of Sunnis reject al-Baghdadi's claim to the caliphate.) Even before al-Baghdadi's reign, the leadership of ISI embraced aggressive jihad and directed it mainly against neighboring Shi'ites (whom ISI and now ISIS members generally regard as unbelievers).