The Islamic State in West Africa Province (ISWAP), a splinter of Boko Haram, is growing in power and influence. From its territorial base on the banks and islands of Lake Chad, this jihadist group is waging a guerrilla war across north-eastern Nigeria and elsewhere on the lake’s periphery. By filling gaps in governance and service delivery, it has cultivated a level of support among local civilians that Boko Haram never enjoyed and has turned neglected communities in the area and islands in Lake Chad into a source of economic support. If Nigeria and its neighbouring Lake Chad states want to sever the bond between ISWAP and these communities – and they should – then they cannot stop with countering ISWAP in battle. They will need to complement military action by filling the service and governance gaps that ISWAP has exploited. This report explores how and why ISWAP emerged from Boko Haram, how it has gained ground both territorially and politically against Shekau’s JAS faction, and how it uses guerrilla tactics to challenge regional armies, particularly Nigeria’s. It focuses in particular on ISWAP’s efforts to forge links to the rural population, and how these ties have become a source of its strength. The report considers what Nigerian and other government authorities are doing to provide their own governance and services and to encourage its own forces to conduct counter-insurgency operations humanely and in a manner that protects civilians. It also makes suggestions for how they might raise their game in order to deny ISWAP the competitive advantage that it seeks.