a prominent Georgetown University counterterrorism expert and field researcher has published his findings based on extensive interviews with former ISIS members which identifies Saudi Arabia as a key source of the now defunct Islamic State's prior rapid growth. 

The findings were summarized in the Government and Technology Services Coalition's Homeland Security Today online journal, and authored by Georgetown University professor Ahmet Yayla, who during the past four years has interviewed over 40 ISIS defectors in Turkey while conducting on the ground research along Syria's border.

Yayla's findings entitled, To Truly Fight Terror, Counter Salafist Jihadist Ideology First, confirm that:

"The majority of the ISIS shaykhs (imams and teachers) who were preaching in ISIS-controlled territories and schools were from Saudi Arabia."