This paper reflects on the links between the production of knowledge on security and the production of regional space in West Africa. Indeed, the reinvestment of West Africa by international actors such as the EU and France driven by their security priorities is ‘dismantling’ West Africa into smaller ‘security regions’ such as the Sahel and the Gulf of Guinea. The argument given to justify this shift refers to the need to be flexible and efficient when facing the emergence of new regional security dynamics linked to fluctuating geographical boundaries of networks of organised crime and terrorism. This raises important questions on how these new dynamics are used and evidenced to justify this ‘dismantlement’ of West Africa and with what consequences. Hence, drawing on international political sociology and critical geography, the paper asks how, by whom, and why security is constantly spatialised in the production of knowledge on regional security. It also examines how the West African political space is reorganised accordingly.