The Sahel, often seen as a haven for armed radical groups, this area is the latest new frontier in the West’s counter-terrorism campaign. This report concentrates on a vertical axis between southern Libya and Northern Nigeria, with a relatively stable but extremely vulnerable Niger at its centre. Although outside attention has largely been on the region stretching from Mauritania to Chad, the porous borders and vast desert areas where national authorities struggle to exert control mean that the stability of any one state is acutely dependent on that of its neighbours. Libya’s 2011 civil war resulted in an outflow of arms and fighters that in part explains the crisis that began in Mali in 2012 and continues.1 Attempts at a managed transition in Libya, the region’s former political hegemon, have derailed, and the chaos that has engulfed it and brought it to the brink of all-out war threatens to further destabilise its neighbours.2 Equally, the power vacuum and ethnic divisions in Libya’s south are drawing in disruptive actors from other states, including Chad, Mali and Niger. Western intelligence services consider Libya’s south west (the Fezzan) and the Lake Chad Basin (spanning the borders between Nigeria, Chad, Cameroon and Niger) key centres of jihadism.3 They are also two largely unexplored areas of potential hydrocarbon wealth in the wider resource-rich region and at the same time transit hubs for the smuggling of people and illicit goods. This report maps the political and security landscape. Particular emphasis is placed on transregional dynamics and political economies that link criminal, radical and political groups and interests. It analyses risks, not least that posed by the rapidly growing and increasingly embittered youth population, and assesses whether current policies and actions by national, regional and wider international actors to curb extremism and radicalisation.