On July 26th, a military junta overthrew Niger’s democratically elected president, Mohamed Bazoum. International condemnation followed culminating in the ECOWAS order, on August 10th, to deploy “its standby force to restore constitutional order in Niger”.
In an excellent article published on West Point Lieber Institute, Professors Russell Buchan and Nicholas Tsagourias argued that an ECOWAS military intervention would be legal because it has been invited, either in an abstract treaty-based manner, or based on an invitation by President Bazoum. As I argue below, I respectfully disagree: The argument of an abstract treaty-based invitation not supplemented by an ad hoc consent has no support from the AU nor the ECOWAS practice. In any case, Niger has clearly revoked its consent to the relevant treaty. As to an ad hoc invitation by the deposed President, Mr. Bazoum does not seem to enjoy the required international recognition to consent to a military intervention in the context of competing governments. Accordingly, the envisaged military intervention would be illegal and, consequently, the current threat to use force too. […]
An authorization by the Security Council may extend to regional organizations “But no enforcement action shall be taken under regional arrangements or by regional agencies without the authorization of the Security Council.” (Article. 53-1). Challenging the Security Council’s monopoly in this regard would run counter to Article 103 of the Charter according to which UN obligations prevail over any other obligations of member states. This probably explains that, in the case of Niger, ECOWAS called on the UN “to support its efforts to ensure a quick restoration of constitutional order in Niger”. […]
My conclusion is that the proposed use of force against Niger without prior authorization from the Security Council would be illegal. For this intervention cannot be lawfully justified by an uncontested anticipatory or ad hoc consent in the current context. Accordingly, ECOWAS responses risk being regarded themselves as an illegal threat to use force prohibited under Art. 2-4 of the Charter, with associated international responsibility. Läs artikel