Abstract: The Reina nightclub attack in Istanbul on New Year’s Eve made clear the immense scale of the Islamic State threat to Turkey. Investigations have shed new light on the group’s command and control over sleeper operatives in Turkey and the large network of clandestine cells and logistical and financial support elements it has set up to sustain terrorist activity. Turkish government complacency has allowed the threat to grow, as have purges of experienced counterterrorism professionals, including those after last year’s failed coup. As the Islamic State shows signs of crumbling in Syria and Iraq, Turkey now faces a nightmare scenario of a mass influx of Islamic State fighters into its territory.

Ahmet S. Yayla, Ph.D. is the Deputy Director of the International Center for the Study of Violent Extremism (ICSVE) and Adjunct Professor at the Department of Criminology,
Law And Society at George Mason University. He Formerly served as Professor and the Chair of the Sociology Department at Harran University Şanlıurfa, Turkey and before that as Chief of Counter-terrorism and Operations Division for the Turkish National Police and Chief of Police in Şanlıurfa. Dr. Yayla earned both his Master's and Ph.D. degrees in Criminal Justice and Information Science from the University of North Texas in the United States. Dr. Yayla's research focuses mainly on terrorism, radicalization and countering violence extremism (CVE).