RT Article T1 ISIS Cohort Transnational Travels and EU Security Gaps: Reconstructing the 2015 Paris Attack Preplanning and Outsource Strategy JF Terrorism and political violence VO 33 IS 4 SP 806 OP 835 A1 Zoli, Corri A1 Williams, Aliya Hallie A2 Williams, Aliya Hallie LA English YR 2021 UL https://krimdok.uni-tuebingen.de/Record/175909465X AB We explore the underappreciated role of organizational tactics in terrorist violence in an understudied single case: ISIS’s execution of the November 13, 2015 Paris attacks. It is one of the first systemic reconstructions of the journeys made by two ISIS strike cohorts in the coordinated attacks, as teams traveled from the Levant to Europe. In contrast to other high-profile attacks, terrorism scholars have not undertaken a detailed reconstruction of this event, even while open source information is now available. By examining the transnational travels of foreign terrorist fighters, we identify ISIS’s distinctive terrorist outsourcing strategy in which operatives used their experiences to adapt to changing security conditions, while EU governments revealed limited responses. Both elements in this tightly-knit dynamic—terrorist outsourcing savvy using FTFs and EU security policy failures—were necessary to achieve this high-profile attack. The essay contributes to descriptive empirical and theoretical knowledge of terrorist tactical innovation and adaptive operational learning, as these capacities are enhanced by on-the-ground organized networks to increase organizational (versus lone-wolf) campaign success. By using a single case interdisciplinary and exploratory framework, terrorism studies can delve deeper into superficially understood phenomena to isolate concepts with future cross-case value, such as cohorts and tactical adaptation. K1 tactical adaptation K1 Tactical innovation K1 terrorist tactics K1 Security Policy K1 Refugee crisis K1 Migration K1 Paris-Brussels cell K1 Paris attacks K1 Isis K1 transnational terrorism K1 Foreign Terrorist Fighters K1 European Union DO 10.1080/09546553.2019.1598385