Domestic Courts and the States’ Obligation to Prevent Genocide and Serious Violations of IHL: The Brussels Court of Appeal’s Interlocutory Judgment of 16 March 2026

On 16 March 2026, the Brussels Court of Appeal (hereafter, the “Court”) issued an interlocutory judgment in summary proceedings (référé) concerning the alleged failure of the Belgian State to comply with its international obligations in relation to the risk of genocide and serious violations of international humanitarian law (“IHL”) in Gaza (hereafter, the “Judgment”). 

The case was initiated on 22 July 2025 against the Belgian State by way of summary proceedings by several civil society organisations – namely the Belgian-Palestinian Association (“Association belgo-palestinienne”) and the National Coordination for Action for Peace and Democracy (“Coordination Nationale d’Action pour la Paix et la Démocratie”) –, together with two individual (Palestinian) applicants (together, the “Appellants”). 

While the proceedings remain ongoing, the interlocutory Judgment already constitutes an interesting intervention by a domestic appellate court in the enforcement of international obligations of prevention. This post briefly outlines the factual and procedural background of the litigation before examining the Court’s key legal findings.

Factual and Procedural Background

The Appellants sought an order requiring the Belgian State, under penalty of a daily fine, to comply with its international obligations “in light of the (risk of) genocide in the Gaza Strip and the ongoing violations of international humanitarian law and international law in both the Gaza Strip and the occupied West Bank” (§4). 

They requested three categories of urgent measures (§§24-27 and the NGOs’ press release of 23 March 2026): (1) the closure of Belgian airspace to the transit of arms and military equipment destined for Israel, including goods with potential dual use (hereafter, the “First measure”); (2) restrictions on economic relations with Israeli settlements; and (3) the suspension or denunciation of the EU-Israel Association Agreement.

While the second and third measures were dismissed at the appeal stage – on grounds of State discretion, separation of powers, and lack of urgency (§§51–52) – the Court partially upheld the appeal with respect to the First measure. The analysis below therefore solely focuses on the Court’s reasoning in relation to that measure. Based on the division of competences within the Belgian federal system, the Court confined its analysis to matters within federal jurisdiction, namely the authorisation of overflight and non‑customs (technical) transit of aircraft carrying arms, military equipment and dual‑use goods to Israel or the occupied Palestinian territories.

The Court’s Key Legal Findings

The Court firstly indicated that Article I of the Convention on the Prevention and Punishment of the Crime of Genocide (hereafter, the “Genocide Convention”) and Common Article 1 of the Geneva Conventions (hereafter, “Common Article 1”) – which require States Parties to ensure compliance with these conventions – have direct effect in domestic law (§7). This means, as the Court notes, that these provisions may be invoked directly by an individual before a domestic court.

The Court was thus required to assess, as a matter of marginal review, whether, in the face of a serious risk of genocide and serious violations (“violations graves”) of the Geneva Conventions by a State Party, the Belgian State had acted within the limits set by law and as a “normally prudent and competent authority placed in the same circumstances” (§7). 

Interim relief in Belgium is an emergency procedure that allows a party to obtain a provisional order from the presiding judge of the competent court to prevent imminent harm. The key requirements are urgency and a prima facie case.

Urgency

Regarding the First measure sought, the Court referred to the preamble to the Royal Decree adopted on 18 January 2026 by the Belgian government “prohibiting flights over Belgian airspace and technical stopovers by aircraft transporting military equipment from Belgium to Israel and the Occupied Palestinian Territory” (hereafter, the “Royal Decree”). This preamble addresses the urgency of “immediately” prohibiting such flights, which were “likely to lead to Belgium breaching its international obligations”. 

The Court also referred to the caselaw of the International Court of Justice (the “ICJ”), which uses the test of knowledge of a serious risk of an act of genocide to determine when a State’s obligation to prevent genocide is engaged. Uncertainty as to whether genocide will ultimately be committed is not sufficient to absolve the State from potential responsibility for failing to act, since it is sufficient that the State was aware of the existence of a serious risk (§37) (ICJ, Judgment of 26 February 2007, Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Serbia and Montenegro), §431). 

On this basis, the Court found that the requirement of “urgency” was met for the First measure (§38).

Prima facie case

The Court considered that “the grave risk of genocide, crimes against humanity and serious violations of the Geneva Conventions” being committed in the Gaza Strip has been known at least since the ICJ’s order of 26 January 2024 indicating provisional measures in the proceedings instituted by South Africa against Israel (§44). In this respect, it should be noted that the ICJ’s decision addressed only the risk of genocide, and not the existence of risks of crimes against humanity or serious violations of the Geneva Conventions.  

The Court’s reasoning here reflects a broader understanding, advanced in recent scholarship, that the indication of provisional measures by the ICJ confirmed the existence of a serious risk of genocide and consequently activated preventive obligations for third States.

The Court further noted that the gravity of the situation in the Gaza Strip required the States Parties to the Genocide Convention and the Geneva Conventions – including Belgium – to take all measures reasonably within their power (i.e. an obligation of means) to prevent the commission of the crime of genocide, crimes against humanity and serious violations of the Geneva Conventions (§44). 

The Court stressed that the Belgian State waited for more than a year after the ICJ’s January 2024 order before taking any coordinating initiative on arms exports to Israel or the occupied Palestinian territories (§44). The Court thus concluded that, prima facie, the Belgian State had breached its international obligations, in that it did not immediately take all measures reasonably within its power to prevent the commission of crimes in the Gaza Strip.

As the Court noted, the Appellants’ initial application for the First measure became partially moot on the date of the adoption of the Royal Decree in January 2026 (§45). Regarding the transit of dual-use goods, the Court emphasised that the Belgian State had failed to explain what measures it had taken that were reasonably within its power. The Court therefore ordered that the proceedings be reopened at a later date in this respect (§46).

Obligation of prevention in IHL

The Judgment is innovative. The Court applies the international threshold of “knowledge of a serious risk” – the standard triggering the obligation to prevent genocide stricto sensu since Bosnia and Herzegovina v. Serbia and Montenegro – as the threshold to trigger a positive obligation to prevent serious violations of IHL. The Court explicitly relies on Common Article 1 as the legal basis for an obligation of prevention incumbent upon third States not party to the conflict. This reflects an expansive reading of the obligation to ensure respect enshrined in Common Article 1 (which includes both an internal and an external dimension).

It is well accepted that, in its external dimension, the obligation to ensure respect for IHL requires States to take all feasible measures to ensure that parties to an armed conflict – beyond persons under their authority (internal dimension) – including other States and armed groups, respect IHL. States thus have positive obligations. In its Commentary on Common Article 1, the ICRC considers that this obligation is not limited to an obligation to put an end to ongoing IHL violations, but also includes an obligation to prevent such violations from occurring, notably through measures such as “conditioning, limiting or refusing direct or indirect arms transfers”.

According to this view – here expressly endorsed by the Court with respect to serious violations of IHL – States’ positive obligations of prevention may be triggered even before a breach has occurred, provided that the risk of such breach is known. 

Similar issues have recently been brought before the ICJ in the case Nicaragua v. Germany, where Nicaragua argues, inter alia, that the continued arms transfers by Germany – a third State – may amount to a violation of its obligations under Common Article 1. Although the ICJ has not yet ruled on the merits, these proceedings, together with recent domestic practice – such as the suspension of export licences for F-35 parts to Israel by domestic courts in the Netherlands – suggest a broader trend towards the judicial recognition of risk‑triggered obligations incumbent upon third States under IHL.

Conclusion

By finding that the Belgian State had failed, at the relevant time, to take all measures reasonably within its power to prevent the alleged violations, the Court demonstrates how obligations of prevention – long discussed in international caselaw and doctrine – can be concretely interpreted and judicially enforced at the domestic level.

At a time when the effectiveness of international law is widely debated, this case highlights the potential role of domestic courts in translating what may seem to be abstract international obligations into legally reviewable and enforceable ones. That said, the Judgment is interlocutory, and it remains to be seen what the judge ruling on the merits will ultimately decide.