This report represents the first publication in ISD’s new “Horizons” series, launched to examine emerging trends related to violent extremism or CVE.

Whilst the term “foreign fighter” is commonly associated with these individuals joining Islamic State (IS) and other extreme Islamist groups, there has been far less attention on the hundreds of other foreign fighters that have travelled to fight against IS. This report builds on ISD’s research into the Islamist foreign fighter and female migrant phenomenon, and is based on a dataset of 300 anti-IS foreign fighters. It sheds light on this understudied group, examining who they are, who they are fighting with, and why they are prepared to participate in a far-away conflict. It also considers the legal frameworks of the countries providing the largest numbers of anti-IS fighters and the possible future implications for the fighters themselves, as well as their national governments.