This study evaluates the impact of foreign terrorist organization (FTO) designation, a core US counterterrorism tool that unlocks legal, financial, and administrative penalties for terrorist groups, against Salafi jihadist terrorist organizations. Using publicly available data from 2001 to 2018, this research takes a quantitative and qualitative mixed methods approach to evaluate if FTO designation of Salafi jihadist terrorist groups alters their behavior by reducing terrorist membership or changing their attack patterns and lethality. The quantitative portion examines the impact of designation across three primary dependent variable behavior categories: group and membership size; attacks and lethality; and targeting. The qualitative portion looks at the range of possible best to worst case behavior outcomes for groups after designation and seeks to determine which, if any, designation-associated activities drove a reduction in violence.

In this study FTO designation did not advance US policy objectives of reducing terrorist group and membership size, decreasing the number and lethality of attacks, or hardening targets against Salafi jihadist attack. Post-designation Salafi jihadist areas of operations experienced overall growth in the number of groups and membership. FTO designation reverses some pre-designation trends in rising attack frequency and lethality, but the results are not statistically significant. Moreover, designation does not significantly impact group targets or attack type.

The qualitative case studies use US government reported data on designation-associated activities alongside captured media to explain variance in group outcomes post-designation. The case studies reveal that a terrorist group’s international versus national presence prior to designation better explains variation in outcomes than designation-associated activities. Groups able to flex across national boundaries were seemingly more resilient to CT pressure. The most international group was the most unaffected by designation, while the most nationally focused group was the most impacted.

While FTO designation was not causally linked to the desired Salafi jihadist behavioral outcomes, the directional shift in some groups attack frequency and lethality shortly following designation suggest designation’s impact warrants further study, including gathering improved official data and yearly metrics on designation-associated effects. As the US reduces its CT footprint, FTO designation and associated metrics can help guide future operations to target Salafi jihadist groups more efficiently, informing future US government CT efforts.