This publication seeks to shed light on the transnational reach of Boko Haram and regional responses to the security threats emanating from this group. Attempts by the Nigerian security services have led to the escalation of attacks and an expansion of Boko Haram’s activities from its stronghold in Nigeria’s Northeast region even beyond its borders. The recruitment of fighters from neighbouring countries, the acquisition of military equipment of foreign origin, access to global communication networks, and the cross-border nature of their operations illustrate the necessity of an international and regional approach to contain Boko Haram. At the same time, the Economic Community of West African States (ECOWAS) seems affected by its biggest and most influential member state, Nigeria, being oriented first and foremost towards resolving internal security challenges.