Fragmenting West Africa: how international sanctions imposed by ECOWAS led to the rise of the Alliance of Sahel States

The withdrawal of Mali, Burkina Faso, and Niger from the Economic Community of West African States (ECOWAS) and their creation of the Alliance of Sahel States constitute the most serious institutional rupture in the organization's fifty-year history. Recent scholarship associates ECOWAS's post-coup sanctions with this fragmentation, yet the causal mechanism connecting coercion to coordinated exit has been neither specified nor tested against rival explanations. This article traces that mechanism through a most-similar systems comparison, applying Bayesian process-tracing tests to a five-step pathway running from sanctions-induced material disruption, through regime legitimation discourse and inter-junta solidarity, to collective withdrawal. The evidence satisfies the designated test at each observable step. Sanctions-induced hardship was converted into a rally-around-the-flag discourse fusing the three regimes' legitimation strategies. Rival explanations account for the realignment's direction but not it's timing or coordinated form. Comprehensive sanctions within regional communities therefore risk institutional self-harm.