From the Lake Chad Basin to the Sahel region, insecurity in the West African sub-region is fast deteriorating due to the activities of organised criminal gangs and violent extremists. This has claimed the lives of thousands and displaced many others. The situation is further exacerbated by the proliferation of small arms and light weapons (SAWLs) through porous national borders and contested spaces. The fragile statehood that characterises these nation-states, reflected through poor governance and weak institutions implies their incapacity and continued struggle towards effective border governance. While previous studies have highlighted the causes, and challenges associated with the insecurity impasses across the sub-region, this chapter draws attention to the less apparent incapacities of the sub-national entities that contribute towards fragility within these states and how the continued incapacity affects the provisioning of effective border governance. The absence of this further contributes to the deteriorating human insecurity situation across the West African sub-region. The qualitative study, which draws on secondary sources of data from academic journal articles, books, and local and international news reportage, therefore advances the argument on sub-national state fragility by examining how it contributes to the proliferation of small arms and light weapons (SAWLs), and its implications on regional peace, security, and stability in West Africa.