" An American air strike ended Zarqawi’s life in June 2006, and by the end of the decade al-Qaeda in Iraq had been decimated. But in 2011 two events conspired to revive its fortunes: the outbreak of civil war in Syria and the withdrawal of all U.S. forces from Iraq. Now known as ISIS, the group rose from the ashes and rushed into the power vacuum along the Syria–Iraq border. "

― Daniel Silva , The Black Widow (Gabriel Allon, #16)