Al-Qaeda leaders regard liberal Muslims,Shias, Sufis and other sects as heretics and have attacked their mosques and gatherings. Examples of sectarian attacks include the Yazidi community bombings, the Sadr City bombings, the Ashoura Massacre and the April 2007 Baghdad bombings. Since the death of Osama bin Laden in 2011 the group has been led by Egyptian Ayman al-Zawahiri.
Al-Qaeda's management philosophy has been described as "centralization of decision and decentralization of execution." It is thought that al-Qaeda's leadership, following the War on Terror, has "become geographically isolated," leading to the "emergence of decentralized leadership" of regional groups using the al-Qaeda "brand".
Many terrorism experts do not believe that the global jihadist movement is driven at every level by al-Qaeda's leadership. Although bin Laden still held considerable ideological sway over some Muslim extremists before his death, experts argue that al-Qaeda has fragmented over the years into a variety of regional movements that have little connection with one another.Marc Sageman, a psychiatrist and former Central Intelligence Agency (CIA) officer, said that al-Qaeda is now just a "loose label for a movement that seems to target the West." "There is no umbrella organisation. We like to create a mythical entity called [al-Qaeda] in our minds, but that is not the reality we are dealing