Aaron Zelin, a Washington Institute expert on jihadist movements, joined with Evan Kohlmann and Laith al-Khouri of Flashpoint Global Partners to prepare this study charting the evolving role of Sunni foreign fighters in Syria's ongoing war. Below is an excerpt; download the PDF to read the full report, complete with charts, tables, photos, and more.

Since the beginning of the armed Sunni uprising against the Alawite Assad regime in Syria in 2011, a growing number of foreign fighters from across the Middle East (and indeed, around the world) have eagerly flocked to join the underdog rebels on the battlefield. Any serious effort to study this motley crew of foreigners is inherently complex. To help gauge the importance and demographics of these fighters, the authors engaged in an exhaustive ten-month effort to find and catalogue their biographies and assemble photographic and video evidence documenting their personal narratives. Much of this material came to light after these various men were "martyred" in combat, in the form of eulogies posted on password-protected jihadist web forums, Facebook pages, and regional media sources.

Indeed, social networking platforms like Facebook and Twitter have provided a critical online bedrock for foreign fighters in Syria, giving them a constant avenue for communication and an open path to share critical information, solicit contributions, and recruit fighters. Each day on Facebook, new names and photos of deceased foreign fighters are posted by rebel supporters who hope that their willingness to sacrifice will inspire others to follow in their footsteps. Though there have been multiple major foreign fighter mobilizations within the Sunni community since the early 1980s, this is the first time that researchers have gained access to such a substantial amount of detailed, original data to analyze...