This is a great piece by Aaron Stein and Noah Blaser explaining the detailed breakdown of the network behind Turkey’s ISS bomb attacks.

“The culprits of all four attacks were members of a single cell of Islamic State (ISIS) from Adiyaman, a pious, Kurdish majority city of 220,000 in southeastern Turkey. While the group has been cast in Turkish media as an opaque network of ISIS-inspired youth, its key members spent time in northern Syria in 2013 and 2014, and were all recruited by a single individual after returning to Turkey. At its peak, the cell numbered at least 31 core members, including at least four foreign wives who had connected with the group in Syria, according to information collected by the two authors.”

Read more here:
The Islamic State’s Network in Turkey