This paper examines the flow of foreign fighters into Syria from Egypt and the GCC countries. It analyses the profiles and stories of some Egyptian and Gulf fighters who have travelled to Syria since 2011, and discusses the different types of drivers leading an individual to become a fighter in ISIS. It underscores the importance of the “triggers” that are mainly personal drivers in comparison to the root causes, and contextual drivers. These triggers include personal grievances, wanting to play a leading role or looking for an opportunity, as well as emotional reactions to the dynamics of the conflicts. This discussion is important in identifying the needed policies to counter this phenomenon as discussed in the conclusion.