Art. IX Reservations to the Genocide Convention Are Here To Stay: A Response to Diamond

[Michael A Becker is Assistant Professor of International and European Human Rights Law at Trinity College Dublin]

On 5 March 2025, Sudan instituted proceedings against the United Arab Emirates (UAE) at the International Court of Justice (ICJ) in relation to alleged violations of the 1948 Convention on the Prevention and Punishment of Genocide. Based on allegations that UAE is supporting genocidal acts by the Rapid Support Forces in West Darfur against the Masalit group, Sudan’s claims raise important questions about the nature and scope of complicity in genocide. Nonetheless, it is very unlikely that any of these factual allegations or legal claims will be heard or decided by the ICJ. Because the UAE made a reservation to Article IX when it acceded to the Genocide Convention in 2005, the ICJ can be expected to conclude that it lacks jurisdiction over the dispute. Art. IX is the provision by which states consent to ICJ jurisdiction over disputes relating to the interpretation, application, or fulfilment of the treaty.

This makes the recent Opinio Juris post by Yonah Diamond (“The Invalidity of Art. IX Reservations to the Genocide Convention”) especially timely. Sudan has suggested that it will seek to challenge UAE’s Art. IX reservation on the basis such reservations are incompatible with the object and purpose of the Genocide Convention. This is also the argument that Diamond sets out to make. However, Diamond takes a normative position on the undesirability of Art. IX reservations that fails to take a full view of the relevant history surrounding the validity of such reservations or the doctrinal basis for preserving the status quo. 

Decades of practice at the ICJ support the view that Art. IX reservations are valid as a matter of treaty law. In 1951, the Reservations to the Genocide Convention advisory opinion established the principle that reservations are permissible unless incompatible with the treaty’s object and purpose. The question arose precisely because so many states that sought to join the newly-adopted Genocide Convention had made Art. IX reservations when doing so. The rule articulated by the ICJ (later codified in Article 19 of the 1969 Vienna Convention on the Law of Treaties) paved the way for those reserving states to be considered parties to the Genocide Convention and confirmed the treaty’s entry into force. Ultimately, the Court treated reservations (including to Art IX) as the necessary cost to obtaining as wide a degree of participation as possible. In contentious cases since then, the Court has not questioned the validity of Art. IX reservations. Consider the Court’s acceptance of the validity of Art. IX reservations in the 1999 Legality of Use of Force cases against Spain and the United States, as affirmed more recently in the 5 June 2023 Order on the Admissibility of the Declarations of Intervention in Ukraine v Russia (see paras 93-96).

Diamond does briefly mention Armed Activities on the Territory of the Congo, where the ICJ in 2006 directly rejected the Democratic Republic of the Congo’s challenge to the validity of Rwanda’s Art. IX reservation (see paras 64-69) . In Diamond’s view, the Court ‘evidently erred’ in delineating the treaty’s object and purpose based on a substantive/procedural distinction and by failing to credit the jus cogens status of the genocide prohibition. One can disagree with the Court’s reasoning, but I don’t see how we can describe this as manifest error. Diamond’s argument seems to be that recourse to the ICJ is the only practical means to implement or enforce the Genocide Convention. Despite the uptick in ICJ cases relating to the Genocide Convention, this is not the case. In principle, acting pursuant to Article VIII of the Genocide Convention, states can turn to the UN General Assembly, the UN Security Council, or the UN Human Rights Council. Compliance might also be pursued through domestic courts or by recourse to countermeasures. Some states might also believe that the goals of the Genocide Convention are best pursued through international criminal law and, in particular, the International Criminal Court. 

In short, a judgment by the ICJ is not the only means to seek to give effect to the substantive obligations set forth in the Genocide Convention. I am not claiming that any of these alternative methods is likely to be especially effective (or at least any more effective that ICJ litigation). But they exist, and I think the ICJ was correct in 2006 to note that opting out of ICJ dispute settlement does not inherently compromise the goal of preventing and punishing the crime of genocide (even if it might make prevention and accountability more difficult, and even if it is preferable for states to accept Art. IX).

Ultimately, Diamond is making a normative argument that Art. IX reservations should be deemed invalid, at least based on developments since the 2006 judgment in Armed Activities (DRC v Rwanda). Yet from a doctrinal perspective, the fact that the ICJ has confirmed the standing of non-injured states to bring Genocide Convention cases (see, e.g., the 2022 judgment on preliminary objections in The Gambia v Myanmar (paras 106-114)) does not bear on the validity of Art. IX reservations. The same goes for the phenomenon of “mass intervention” by third states in these cases. These notable trends are not sufficient to establish a peremptory norm of general international law “requiring a State to consent to the jurisdiction of the Court to settle a dispute relating to the Genocide Convention”, as the Court put it in Armed Activities (para 69). The fact that many states see the ICJ as an important and (maybe) useful way to seek compliance with the Genocide Convention does not in and of itself mean that Art. IX reservations are incompatible (or are no longer compatible) with the treaty’s broader goals.

This is not to say that the validity of Art. IX reservations has not been contentious (including among ICJ judges), and Diamond notes correctly that some states have lodged objections to Art. IX reservations at various times. However, the majority of states parties to the Genocide Convention have not done so (including Sudan, which did not object to UAE’s Art. IX objection at the relevant time). Whether state practice of this sort should be the ultimate arbiter of a treaty’s object and purpose is debatable, but this record of tacit acceptance weighs against Diamond’s position.  Taking a broader view, it remains the case that most international human rights treaties treat third-party dispute settlement as optional (and sometimes make this explicit, as in Article 30(2) of the 1984 Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment). Given the substantive similarities between the Genocide Convention and the Torture Convention, the optional nature of ICJ dispute settlement under the Torture Convention further undercuts the argument that Art. IX reservations are inherently incompatible with the object and purpose of the Genocide Convention.

Diamond’s piece closes by describing Art. IX reservations as a technicality. This strikes me as unfortunate. It may be that some states parties to the Genocide Convention would never have ratified or acceded to the treaty without the possibility of excluding ICJ dispute settlement. If the ICJ were asked to address this question today (as may happen in the new proceedings instituted by Sudan), the ICJ would be wise to proceed in a manner consistent with its past practice—an approach that gives primacy to state consent. Indeed, this may be an especially inopportune moment to take steps that might further destabilize an international legal system already facing very serious threats and dramatic change. 

None of this means that I endorse the possibility of giving states the option to withhold their consent to third-party dispute settlement as a general matter. In a world in which international affairs are far more judicialized than they were in 1948, it should generally be feasible and good policy to treat the acceptance of compulsory dispute settlement as the ‘price of admission’ to human rights treaty regimes. But this neither can nor should undo decades of practice under the 1948 Genocide Convention, which has cemented the optional nature of ICJ dispute settlement under that instrument.