The situation in Niger remains tense following the military’s July 26 coup d’état. On Sunday, August 6, a one-week ultimatum issued by the Economic Community of West African States (ECOWAS) expired. The 15-member regional bloc had previously threatened to impose sanctions on the military government in Niger and to “use military force in Niger if necessary” if power was not returned to the democratically elected government. Mali and Burkina-Faso, who are both currently suspended from their membership in ECOWAS following coups, have sided with Niger’s military government, stating that they would consider any military intervention against Niger as a “declaration of war against Burkina Faso and Mali.”

Whether ECOWAS will follow through on its threat to intervene militarily in Niger is still uncertain at this point. While the current chairman of ECOWAS, Nigerian President Tinubu stated on Thursday, Aug. 10, that ECOWAS States will first exhaust all diplomatic options to ensure a swift return to constitutional governance in Niger, he also stressed that “no options have been taken off the table,” including the use of force as a last resort. In its Final Communiqué, ECOWAS decided to order the deployment of a Standby Force. The regional organization’s threat to use force raises a number of legal problems under the body of international law governing the use of force (jus ad bellum).

According to Article 2(4) of the United Nations Charter, the “threat or use of force” is prohibited in international relations. Thus, the mere threat of force by ECOWAS on July 30 could constitute a violation of the prohibition of the use of force. The U.N. Charter does permit two exceptions to the prohibition on the use of force: a U.N. Security Council authorization under its U.N. Charter Chapter VII powers to respond to “any threat to the peace, breach of the peace, or act of aggression,” or an armed attack against an ECOWAS member State within the meaning of Article 51 of the U.N. Charter governing individual or collective self-defense. However, at present neither condition is fulfilled. In particular, nothing in the ECOWAS States’ threat of force indicates that its implementation is dependent on the prior approval of the U.N. Security Council, which is explicitly required in case of “enforcement action” taken under regional arrangements according to Article 53(1) of the U.N. Charter. Since there is no general authorization for pro-democratic intervention under international law, the only possible legal basis for a potential ECOWAS military intervention would therefore be an invitation by Niger extended to ECOWAS to use force in Niger.

An Ad Hoc Invitation?

It is generally accepted that the use of military force is permissible under international law when a State invites another State or a regional organization to use force on its territory. While scholars debate over whether an “intervention by invitation” is permissible in a civil war (for an overview of the discussion see here), there is broad agreement that a valid invitation must be issued by the government of a State (as the International Court of Justice (ICJ) held it its 1986 Nicaragua judgment para. 246). Thus, an ad hoc invitation could only exist if the ousted government of Niger’s President-elect Mohamed Bazoum issued a valid invitation. In fact, Bazoum has already appealed to the international community, penning an op-ed in the Washington Post “to help us restore the constitutional order,” and one might wonder whether this appeal includes a request to use force if necessary.

The crucial question is, however, whether the Bazoum government can still be considered the government of Niger, and the government that is entitled to issue an invitation. Traditionally, the relevant criterion for determining the legally recognized government has been whether the government exercises effective control over the territory of a State, regardless of how the government acquired that control. According to this view, a government no longer exercises effective control if it has lost control over a sufficiently significant and representative part of the territory. However, especially since the 1990s, considerations based on a State’s internal constitutional legitimacy have increasingly gained ground in international law doctrine and the legitimacy of a government was regarded as the appropriate criterion for recognition. Indeed, there has been a small number of cases in State practice (such as Haiti 1994, Sierra Leone 1997-1998, and Yemen 2015), in which legitimacy considerations have been relied upon to hold on to democratic governments who lacked effective control, or, as in the situation in the Gambia (2017), even to help them into office after an election. It is worth noting that the situation in Niger has in common with these conflicts, that, as in all of them (as has been shown here), the Security Council has issued a statement declaring whom it considers to be the legitimate government (in a July 28 press statement the Security Council called the Bazoum government the “legitimate government”).

Today, scholars widely agree that once recognized by the international community, an incumbent government is, in principle, presumed to remain in effective control of its territory and therefore does not lose the right to invite intervention, even in situations where such effective control becomes “fictitious.” Embracing this view, the legal analysis could end here, and ECOWAS could arguably rely on a potential ad hoc invitation issued from the Bazoum government, which is arguably still the internationally recognized one (as has been affirmed for example here). However, if one took the view, more widespread perhaps in the past than today, which still requires a “minimum of effectiveness” as a prerequisite for a State’s power to invite, an ad hoc invitation would be a rather fragile legal basis for a military intervention by ECOWAS. For it cannot be assumed that the Bazoum government still exercises a minimum of effectiveness, particularly with Bazoum under military confinement, Niger’s military appearing to support the side of the coup plotters, and no clearly significant popular movement backing Bazoum’s government.

Article 25 Lomé Protocol as an Anticipated Invitation? The History of Forward-Looking Intervention Treaties

However, besides an ad hoc invitation, another possible legal basis could come into play, and it remains to be seen whether ECOWAS will invoke it. And this is a treaty provision, that Niger, as a member State of the ECOWAS, has agreed to in Lomé, Togo, in December 1999. In Article 25 of the Protocol Relating to the Mechanism for Conflict Prevention, Management, Resolution, Peacekeeping and Security of the Economic Community of West African States (the “Lomé Protocol”), ECOWAS member States authorized ECOWAS to intervene militarily in its member States in a number of situations, including “in the event of the overthrow or attempted overthrow of a democratically elected government.”

Whether provisions such as Article 25 of the Lomé Protocol, in which States give their consent to a military intervention in anticipation of a conflict, can form an independent legal basis to justify intervention, has received comparatively little attention in international legal debate. This is quite surprising when one considers that Article 25 of the Lomé Protocol is not an isolated phenomenon in State practice. In fact, the practice of granting rights to intervene in an anticipatory manner has a long history. In the 20th century, anticipatory intervention rights were granted mainly in bilateral defense treaties (for an overview of the history of such intervention treaties, see here) and had for a long time been politically highly controversial as they were mainly used to pursue hegemonic interests. A prominent instance in which a State invoked a treaty to justify its use of force was Turkey’s invasion of Cyprus in 1974, for the legal legitimacy of which Turkey invoked Article IV of the 1960 London Treaty of Guarantee, claiming that it gave Turkey a “legal right” to intervene militarily to re-establish the state of affairs in Cyprus as created by the Treaty. Also, the fact that forward-looking intervention treaties have not lost any relevance was most recently demonstrated by the Turkish offensive in northern Syria in the fall of 2019. There, Turkey invoked a 1998 agreement with Syria as part of its legal justification, in which Syria authorized Turkey “to take all necessary security measures” to preserve Turkey’s security within 5 km into Syrian territory – a fact that has been largely overlooked in the international debate (for a legal assessment, however, see here).

In parallel with this development, ECOWAS was not the only regional organization to include an anticipatory intervention clause in its collective security mechanism at the beginning of the new millennium. Following the experience of the humanitarian disasters on the African continent in the 1990s, several other African regional organizations included similarly worded provisions in their collective security mechanisms. The most prominent example is Article 4(h) of the Constitutive Act of the African Union (2000), in which member States granted to the African Union “a right to intervene in a Member State pursuant to a decision of the Assembly in respect of grave circumstances, namely: war crimes, genocide and crimes against humanity.” Other regional organizations that have adopted similar provisions are the Economic Community of Central African States in Article 7 of the Pacte d’Assistance Mutuelle and the International Conference on the Great Lakes Region in Article 4(8) of the Protocol on Non-Aggression and Mutual Defence. The common feature of these protocols is that they can all be interpreted as allowing the respective regional organizations to intervene without prior authorization from the Security Council. While all of the norms mentioned are still in force today, African states have been to date reluctant to invoke them.

The Legality of Anticipated Invitations under the Doctrine of Intervention by Invitation

The growth of these clauses raises a question as to their legality under international law. Where it has been examined in the past, the phenomenon of forward-looking intervention clauses has rightly been studied as a potential form of an invitation to intervene under international law, since treaty intervention clauses ultimately contain nothing more than the (anticipatory) consent of the contracting States to a use of force on their territories in certain cases. Contrary to what is sometimes argued in the literature, concerns about possible normative collisions of anticipatory invitations with principles of the U.N. Charter do not prevail. Anticipated invitations differ from ad hoc invitations in the sense that they are issued on an abstract basis and usually have no temporal proximity to the conflict for which they authorize the use of military force. However, a close examination of the doctrine of consent to the use of force shows that neither a requirement of temporal proximity between an invitation and the subsequent use of military force, nor the existence of a requirement of definiteness of an invitation, can be derived from the law of invitations (see in German here). Thus, just as an ad hoc invitation, an anticipated invitation prima facie falls outside the scope of the prohibition of the use of force contained in Article 2(4) of the U.N. Charter. This finding is not without its problems, given the legal grey areas that still surround the phenomenon of anticipated invitations, and it seems understandable that it raises concerns, given that anticipatory invitations conceivably entail a risk of abuse and the circumvention of the sovereign will of the inviting State.

Anticipated Invitations as an Independent Legal Basis? The Right to Revoke as the Decisive Instrument

Some have argued, that anticipatory intervention clauses, nevertheless, would lack independent legal significance, since in the end, the ad hoc request of the State concerned would always still be decisive and therefore required. This view is also reflected in Article 4(3) of the Rhodes Resolution (2011) of the Institute of International Law. In support of this argument, some scholars point to the past reluctance of States to solely rely on an anticipated invitation.

It is true, the ad hoc will of the inviting State must always be considered at the time of the intervention in question. However, this does not necessarily mean that anticipated invitations could not as such serve as a legal basis. This view is already supported by the fact that if an ad hoc invitation would always be required, the relevant treaty provisions, such as those contained in the relevant African protocols would ultimately be completely without legal significance, a fact that could hardly be reconciled with the context and intention, in which these protocols were created (for a more detailed  argument including a careful analysis of State practice, see here). Rather, the requirement, that guarantees that the ad hoc will of a State is taken into account at the time of the intervention is the inviting State’s right to revoke its invitation, which is based on the principle of sovereignty of States. The right to revoke an invitation “at any time” is firmly anchored in international law (see ICJ, Armed Activities, 2005, para. 47) and overrides the Vienna Convention on the Law of Treaties (VCLT), where an anticipated invitation is issued within an international treaty (for a detailed argument in this regard based on the nature of military intervention clauses, see here). Whether a government is authoritative to revoke an invitation must be assessed according to the same standards as whether the government could invite at the time in question.

By attaching decisive importance to the right of revocation, anticipated intervention clauses may serve as an independent legal basis if the anticipated consent they contain has not been revoked. Furthermore, it might be the examination of the contours and possible limitations of the right to revoke that may prove to be worthy of investigation. For example, it has been considered in scholarship, whether an autocratic government that has overthrown a democratic government should be denied its right of revocation in the period immediately following an overthrow. This limitation of the right to revoke seems to be closely linked to the considerations of the right authority to invite made above. However, such a consideration gains relevance, if the overthrown government can no longer be regarded as the authority to invite and revoke (anymore). Furthermore, it has been considered in scholarship, whether a government may in extreme cases forfeit its right of revocation if it violates its responsibility to protect with respect to its own population, assuming, that the principle of sovereignty of States, which is the basis for the right to revocation, is in itself limited by the responsibility to protect civilians (a consideration which is much more difficult in legal terms; for a discussion of both arguments see here).

Without wishing to take a substantiated position here on either of the possible limitations, in any case it can be stated that it does not in principle seem contradictory to consider limitations of the right to revoke – even in cases, in which a limitation of the authority to invite cannot yet be detected in international law. This is due to the fact, that there is a difference in terms of the principle of sovereignty between binding a government to a disposition, that the (same or previous) government once made by agreeing to a treaty clause – and denying a government the right to invite and revoke from the outset.

Application to the Situation in Niger

If Bazoum is still to be considered to be the President of Niger, as the Security Council seems to hold, he currently retains the power to issue an ad hoc invitation in the first place. Should that be true, then, similarly, no problem would occur for ECOWAS to rely on the anticipated consent by Niger encapsulated in Article 25 of the Lomé Protocol. The power to revoke such consent would similarly rest with the Bazoum government, which, arguably, has not revoked Niger’s anticipated consent.

ECOWAS could then use Article 25(e) of the Lomé Protocol as a legal basis for armed intervention. For the situation in Niger arguably fulfills Article 25(e)’s requirement of the “overthrow of a democratically elected government” and the suspension of Niger’s ECOWAS membership does not relieve Niger from its treaty obligations that were entered into before the suspension.

But the legal analysis would significantly change, if the military junta had become the government of Niger and hence the authority which has the right to consent or to revoke the consent to a use of force.

In this scenario, ECOWAS’ threat to use force would seem to lack legal justification, because then there would be clearly no ad hoc invitation, and because any anticipated consent contained in the Lomé Protocol would then arguably have been revoked implicitly by Niger’s military junta, which has expressed in various statements that it rejects any kind of military intervention against it.

If this were the correct legal starting point, it would be necessary to examine more closely the possibility of a limitation of the right to revoke an anticipated consent in the event of the overthrow of a democratic government, as proposed in international legal scholarship. The political dynamics in Niger illustrate the fact that such a limitation of the right to revoke would give teeth to provisions such as Article 25(e) of the Lomé Protocol, which provides for the protection of the will of a democratically elected government. If such a limitation of the right to revoke did apply here, the protest by the military regime currently in power in Niger, against a possible military intervention, would be legally insignificant, even if this military regime had by now become the government of Niger.


Whether or not ECOWAS will follow through on its threat to intervene militarily in Niger is still uncertain at this point, and it is necessary to say that there are very good policy reasons that caution against such a military intervention: Experts have pointed out that an intervention in Niger could lead to a destabilization of the country with far-reaching consequences for the region and beyond, and that in the worst case scenario, Niger could devolve into a proxy warbetween military juntas and the elected governments of West Africa.

From a legal perspective, the very fact that the regional organization has threatened to use force in Niger makes it necessary to reflect on the legality of the threat. Assuming, that ECOWAS did not intend to violate international law when it issued its threat of force and considering that the existence of a valid ad hoc invitation could at least be questioned in this instance, it is reasonable to assume that its member States might also have had Article 25 of the Lomé Protocol in mind when making their statement.

In any event, the eventual outcome in Niger may draw more attention to the possibility of invoking treaty clauses as a legal basis for the foreign use of force by a State in the future. Ultimately, the risks arising from this possibility will make it necessary to look more closely into certain legal questions related to the right to revoke the anticipated consent encapsulated in such clauses.

IMAGE: Protesters hold placards denouncing the Economic Community of the West African States (ECOWAS) (CEDEAO in French) during a demonstration on Niger’s independence day in Niamey, the capital, on Aug. 3, 2023. (Photo by AFP via Getty Images)