This article examines the evolution of military operations by the Economic Community of Western African States (ECOWAS) and the South African Development Community (SADC) over the last three decades. By looking at constitutional (treaty) developments and organizational practice, it questions whether these sub-regional organizations have displaced the primacy of the United Nations Security Council (UNSC) in matters pertaining to international peace and security, as foreseen in Articles 24(1) and 103 of the United Nations Charter (the UN Charter). The relevance of this question is underscored by the fact that ECOWAS and SADC have engaged in various peace operations since the 1990s. The article concludes that, since all the interventions under discussion were underpinned by the consent of the recognized government, it would be premature to suggest that the practice of African sub-regional organizations amounts to the emergence of a new customary right to engage in ‘first-instance enforcement action’.