"This report, based on over 4,000 leaked personnel records, gave an interesting inside look at who the group was able to bring into the organization and also how the group was trying to manage the large number of recruits. This report breaks down the experience (or lifecycle) of foreign fighters into three stages: pre-departure, in theater, and return. However, because the personnel records used in the previous report do not speak to each of these stages, this report then uses open-source reporting on these fighters to code variables in each of these different stages. Using a dataset of nearly 1,200 foreign fighters from mostly Western Europe and North America, this report offers a more holistic examination of what the fighter flows look like, but also what challenges policymakers and practitioners will face as they continue to deal with this enduring and complicated problem."
Combating Terrorism Center: https://www.ctc.usma.edu/