This paper examines the evolution of the role of defence and security forces in combating insurgencies in the most affected coastal West African states. The case studies offer examinations of states’ efforts to enhance the capabilities of defence and security forces in five areas, namely the expansion, professionalisation, and specialisation, as well as enhancement of multi-agency co-ordination and community relations. They also identify a set of challenges and opportunities surrounding the adoption and implementation of comprehensive strategies to countering violent militancy. Each context is different, but the cases’ commonalities help generate several foundational lessons that defence and security forces and their organisations should consider as they hone and deepen the reforms launched to enhance the operational effectiveness and political legitimacy of their forces. These lessons reinforce the principles and imperatives derived from studies on countering militant groups in the Sahel and West Africa.