Ahmet S. Yayla, Ph.D.is an adjunct associate professor at Georgetown University, Fellow, Program on Extremism, George Washington University. He formerly served as a professor and the chair of the Sociology Department at Harran University in Turkey. He also served as the Chief of Counterterrorism and Operations Department of the Turkish National Police in Sanliurfa between 2010 and 2013. He is the co-author of the newly released book, ISIS Defectors: Inside Stories of the Terrorist Caliphate. Follow him at @ahmetsyayla on Twitter.