Intervention by invitation and the scope of state consent

In July 2023, the democratically elected president in Niger was overthrown in a military coup. The ousted president called on the international community to help restore democracy in Niger and ECOWAS threatened to use force to achieve this objective. This article explores whether ECOWAS’s threat of force was lawful under international law on the basis of the doctrine of intervention by invitation and considers two possible grounds. First, given Niger’s membership of ECOWAS and the AU, it examines whether Niger has consented to intervention under these organisations’ constitutive agreements. Second, it assesses whether Niger’s deposed democratic president can provide ad hoc consent to intervention on the basis of his government’s democratic credentials even though it does not exercise effective control over Niger’s territory and population. More generally, this article uses Niger as a springboard to elaborate on when consent can be invoked as a justification for military intervention.