David Sterman wrote for the CTC Sentinel on the differences between experienced ISIS recruits with prior jihadi experience in Libya and Afghanistan, drawing from New America reports All Jihad is Local: What ISIS’ Files Tell Us About its Fighters and All Jihad is Local Volume II: ISIS in North Africa and the Arabian Peninsula: 

From 2013 through 2014, the Islamic State recruited tens of thousands of fighters from all corners of the globe to fight in Syria and Iraq. The vast majority of these fighters were new to jihad, having never taken up arms before. Yet, the Islamic State also drew a select group of recruits for whom Syria would not be their first jihad. This article examines 219 such fighters who reported prior jihadi experience outside of Syria. It finds that the profiles reported by Islamic State veteran jihadis with experience in Libya and Afghanistan, the two top locations from which Islamic State fighters reported prior experience, are substantially different. Veterans of jihad in Libya are the result of localized dynamics while veterans of jihad in Afghanistan represent a more internationalized jihadi contingent.