Why States Should Think Twice Before Transiting Other States’ Military Equipment to Third States Likely Committing Genocide

[Thomas Obel Hansen is the Beatriz Galindo Distinguished Professor with the Department of International Law, Universidad Carlos III de Madrid (UC3M), co-funded by the Spanish Ministry of Science. He is associated with the Francisco de Vitoria Institute of International and European Studies at UC3M and has a research affiliation with the Transitional Justice Institute, Ulster University.]

Debate has emerged in some countries – for instance Spain, Belgium, Ireland and Italy  – concerning the respective governments’ permitting the use of their infrastructure (typically ports or airports) for transit of other countries’ (typically U.S.) shipments of weapons, munitions, or other types of military equipment (for the sake of simplicity referred to here collectively as ‘military equipment’) to Israel in the context of its campaign in Gaza.

Situations involving direct transfer of military equipment to Israel – subject to litigation before the International Court of Justice (ICJ) and in multiple national jurisdictions – have, for good reason, received a fair amount of attention in recent commentary (see, e.g. the useful overview of litigation in national jurisdictions by Jacques Hartmann et al; Jinan Bastaki’s analysis concerning the duty to prevent genocide; and detailed accounts of domestic litigation, e.g. this piece about litigation before German courts). 

Missing from this debate about provision of military equipment is an assessment of possible breach of obligation for facilitating transit of other States’ shipments of military equipment to a third State allegedly committing acts of genocide. This post sets out the relevant standards under the Genocide Convention and relate these to transit of military equipment en route to Israel. International Humanitarian Law (IHL) and the Arms Trade Treaty (ATT) entail similar prohibitions concerning transfer of military equipment to States committing serious violations, but it’s beyond the scope of this post to discuss the relevant provisions.

I conclude that in so far as a State allows, or fails to inform itself concerning, another State’s vessels or aircraft that transit its facilities which carry in their cargo military equipment subsequently used by a third State which performs acts of genocide, or where there’s a serious risk that it is, the first State may likely be in breach of its obligations under the Genocide Convention. 

The Duty to Prevent Genocide and Transit of Military Equipment en route to Israel

States actively transferring military equipment with awareness that this may be used by the recipient State to commit acts of genocide could, depending on the circumstances, be liable under the complicity standards in Article 3e of the Genocide Convention. States facilitating transit of another State’s military equipment to a third State under the same circumstances are more likely to be in breach of their duty to prevent genocide, set out in Article 1 of the Convention, by omission. 

In the following, the core conditions for breach of that duty are discussed in the context of transit of military equipment en route to Israel.

1. There is “Serious Risk” that the Recipient State is, or will be, Committing Genocide (ICJ Judgment, Bosnia v. Serbia, para 431)

This requirement is satisfied already due to the various Orders by the ICJ in South Africa v. Israel, which have clearly established a serious risk of genocide being committed by Israel in Gaza, since the first Order was delivered on 26 January 2024. Numerous other sources have since established that Israel is committing acts of genocide, or that there is a serious risk that it is (see, e.g., here; here; here; and here). It is safe to conclude that this condition for breach of duty is satisfied at least since 26 January 2024. 

2. The State Facilitating Transit “Learns of, or Should Normally have Learned of, the Existence of a Serious Risk that Genocide is or will be Committed” (ICJ Judgment, Bosnia v. Serbia, para 431)

States facilitating transit will of course be familiar with the January 2024 ICJ Order. As other commentators have explained, the ICJ’s January 2024 order alerted all States that there is a risk of genocide in Gaza, resulting that no State can plead ignorance. Several of the governments alleged to be involved in transit practice have intervened on the side of South Africa in the ICJ case brought against Israel (see, e.g, here and here). Indeed, some of these governments have explicitly stated their view that Israel is committing genocide in Gaza (see, e.g., statements by  Ireland, Spain; and Belgium). This condition for breach of duty is therefore satisfied at least since 26 January 2024.

3. The State Facilitating Transit Fails to “Employ all Means Reasonably Available to them, so as to Prevent Genocide so far as Possible” (ICJ Judgment, Bosnia v. Serbia, para 430)

This standard calls for an “assessment in concreto” of the due diligence measures that can be reasonably taken (ICJ Judgment, Bosnia v. Serbia, para 430). Due diligence measures could in this context involve, among others, seeking clear guarantees from the sending State that relevant vessels or aircraft are not used to transport military equipment to a third State which is in breach of its obligations not to commit genocide, or where there is a serious risk that it is; enhanced scrutiny/ inspections of relevant vessels or aircraft upon transit if there is a suspicion that they carry such cargo; and/ or denial of transit of specific vessels or aircraft where a serious risk has been identified, or it becomes impossible to identify such a risk, for instance due to the action of the sending State. The most viable route may often be the latter. Spain recently took such steps, banning transit through its military bases of U.S. vessels and aircrafts supposedly carrying in their cargo military equipment to Israel; legislators in Ireland have called for similar measures. 

4. The Delivery of Military Equipment Transiting the First State’s Territory Makes a Contribution to the Recipient State’s Commission of Acts of Genocide, or a Serious Risk that it is

This assessment depends on the factual circumstances surrounding concrete transits and the likely use of relevant cargo. This could involve, for instance, looking at the type of military equipment in question (are we talking equipment that is normally used offensively or only in a protective manner). If a State fails to inform itself of relevant facts surrounding transits – as allegedly happens in some cases – this does not necessarily discharge the State facilitating transit from its duties: The obligation to prevent is activated, as others have explained, in situations where “a diligently carried out risk assessment would have brought the risk to the State’s attention”.

Could Alternative Transit Options Exonerate the State Facilitating Transit?

If a State facilitates another State’s use of its ports or airports to transport military equipment to a third State which uses this equipment to commit acts of genocide, or there is serious risk that it is, some might object that the first State’s refusal of transit would not necessarily reduce the risk of genocide for the simple reason that the State sending military equipment could simply rely on other transit options, if the first State denies transit. 

However, the relevant question is not whether using a specific measure would have necessarily prevented the State allegedly committing genocide from doing so altogether or whether genocide would have “occurred anyway”, but rather whether specific action taken by the State under an obligation to prevent could have potentially restrained “in any degree the commission of genocide”: The duty to act “is not dependent on the certainty that the action to be taken will succeed in preventing the commission of acts of genocide, or even on the likelihood of that outcome”. (ICJ Judgment, Bosnia v. Serbia, para 461). 

Relevant Litigation 

There is no jurisprudence at the international level that decisively establishes whether providing military equipment – including failing to restrict the transit of military equipment provided by another State – to a third State allegedly committing acts of genocide amounts to a breach of the first State’s obligations under the Genocide Convention. 

The question whether providing military equipment, to Israel that could “be used in the commission of genocide” can amount to a breach of the obligation to prevent genocide (and the duty to ensure respect for IHL) is at the heart of the case brought by Nicaragua against Germany before the ICJ (Provisional Measures Order, para 2(2)). The Court strongly suggested that a reported significant reduction in German transfers of offensive weapons (so-called “war weapons”) to Israel, as a measure taken due to Israel’s alleged violations in Gaza, was a relevant factor in its decision not to indicate provisional measures (paras 18; 26) (see further here). The Court further reminded (para 24) all States of their obligations “relating to the transfer of arms to parties to an armed conflict, in order to avoid the risk that such arms might be used to violate the [Genocide Convention and the Geneva Conventions].”

Litigation in national jurisdictions similarly tends to focus on situations involving direct transfer of military equipment to Israel. While some cases are still pending, several have been dismissed with reference to plaintiffs’ lack of standing or other procedural rules in domestic law, including rules limiting the courts’ ability to review executive action relating to arms export licenses (see, e.g., the June 2025 judgment by the High Court in London; here and here regarding court decisions in Germany; here and here concerning the April 2025 decisions by the Eastern High Court in Denmark; and the January 2024 judgment by the District Court for the Northern District of California – in which the court strongly suggested that had it not been for the “political question doctrine”, it would have decided differently). 

At least in one case, however, the executive has been ordered to stop transfers of military equipment to Israel (here with reference to corresponding obligations under IHL): A widely discussed decision of the Hague Court of Appeals in February 2024 ordered the Dutch Government to cease export of F-35 components to Israel, on the basis that these “might be used in the commission of serious violations of [IHL]”. While the Dutch Supreme Court recently overturned that decision, it required the government to reassess the authorization to export F-35 parts to Israel (see further here). 

Concerning the specific question of transit, national courts have at least on one occasion ordered governments to end transit of other States’ shipments of military equipment to Israel: In July 2025, the Brussels Court of First Instance ordered the Flemish government to “immediately stop all transit to Israel of defense-related products and other material intended for military use for which no material guarantee is provided that it will be used exclusively for civilian purposes and will not be used in any way that is not permitted.” The Court concluded that “there is a significant and real risk” that the cargo is intended as a “crucial component of defence-related equipment that will be used for acts that can at least be described as genocidal conduct” and/ or IHL violations. 

In separate developments in Belgium, the Walloon Minister-President issued a ministerial decree in May 2025 banning all transits of arms to Israel, as a response to reported transit through Liège Airport (see further here). However, following an appeal brought by Israeli airline ‘Challenge’ (operating at the relevant Airport), the Council of State subsequently annulled that decision, citing procedural issues in the form of lacking consultations.

According to media reports, a case was filed with the High Court in Ireland in July 2025, seeking permission for judicial review concerning the alleged use of Irish airspace for aircraft belonging to other countries that transport military equipment to Israel.

Final Comments

Even if a ceasefire in Gaza is now formally in place, it is not clear that genocide, or a serious risk of genocide, has ended. States that have already ended or paused their transfer – and permission for transit of other States’ shipments – of military equipment to Israel would be wise to keep these measures in place until such a time where serious violations in Gaza have ended. States failing to do so could incur State responsibility and may face additional consequences in domestic law. Restricting transit of military equipment to States committing serious violations sends a strong signal both internationally and domestically that a government will not tolerate its facilities being used to assist other States’ atrocities.

Photo attribution: Photo by Marcin Jozwiak on Unsplash