Attacks on dual-use objects and the prohibition of terrorising civilians: the attacks on Iran’s oil facilities

Late on Saturday, March 7, the Israeli military conducted a series of strikes against several oil storage facilities in and around Tehran, igniting large fires at the facilities. By the following morning, Iran’s capital was reported to be covered in thick smoke from the burning depots. Later on Sunday, reports emerged that “black” rain, saturated with oil, was falling over parts of the city. 

This post examines the attacks through the lens of international humanitarian law (IHL), focusing specifically on the prohibition of acts or threats of violence, the primary purpose of which is to spread terror among the civilian population. Specifically, the post argues that disproportionate attacks on the dual-use objects may, under certain circumstances, qualify as acts intended to terrorise the civilian population. This post, however, does not seek to provide an exhaustive assessment of the legality of the strikes and is necessarily based on the information publicly available at the time of writing. Its conclusions should therefore be regarded as tentative.

The applicable law 

Israel officially confirmed that it conducted the strikes in question (see the update for 7 March 2026 at 23:53). Neither Israel nor Iran are parties to the Additional Protocols (APs) to the Geneva Conventions. Therefore, the law applicable to the strikes is limited to the 1949 Geneva Conventions (GCs) and customary international humanitarian law (CIHL). However, when interpreting the relevant customary rules, reference will be made, where appropriate, to the interpretations of the provisions of API containing the same customary rules.

The scope of the prohibition of spreading terror among the civilian population 

IHL prohibits acts or threats of violence the primary purpose of which is to spread terror among the civilian population (CIHL, Rule 2; the rule can also be found in API, Article 51(2) and APII, Article 13(2)). 

It has been suggested that this prohibition cannot be violated by an attack directed at a legitimate military objective. Specifically, this position has been taken by the ICTY Trial Chamber in Galić, which held that the acts of violence for the purpose of this prohibition “do not include legitimate attacks against combatants but only unlawful attacks against civilians” (¶135; see also, Sassòli, MNs 10.036; Bothe, Partsch, Solf, p. 342, ¶2.3.1.-2.3.2; Logan and Coble). The Trial Chamber’s conclusion on the scope of the prohibition of spreading terror among civilians in Galić rests solely on a reference to the preparatory works of API, which, however, do not substantiate such a restrictive reading. Rather, the references cited merely record drafting proposals that were either not reflected in the final text or, in any event, do not support the exclusion of attacks directed at military objectives from the scope of the prohibition.

Furthermore, already the Appeals Chamber in Galić appears to have expanded the Trial Chamber’s approach, stating that the acts falling under this prohibition are not “limited to direct attacks against civilians or threat thereof but may include indiscriminate or disproportionate attacks or threats” (¶102, emphasis added). The subsequent judgment of the ICTY’s Trial Chamber in Karadžić combined the conclusions of the Trial and Appeals Chambers in Galić, holding that “the acts or threats of violence constituting terror need not be limited to direct attacks on civilians or threats thereof, but may include indiscriminate or disproportionate attacks. In addition, they do not include legitimate attacks against combatants” (¶460). While the wording of the last sentence is confusing from an IHL perspective, the only plausible reading of this statement appears to be that only the attacks against legitimate military objectives that are lawful in all respects under the rules on the conduct of hostilities are excluded from the scope of the prohibition (this appears to have been the view of the ICRC in the final stages of the drafting process, p. 274, ¶51; as well as that of Dinstein, ¶490). 

The view that attacks on legitimate military objectives do not necessarily fall outside of the scope of the prohibition of attacks spreading terror among civilians is further confirmed in the 1987 Commentary, according to which “[t]his provision is intended to prohibit acts of violence the primary purpose of which is to spread terror among the civilian population without offering substantial military advantage” (¶1940, emphasis added). Moreover, the provision has been progressively referred to even beyond the contexts of direct attacks against civilians, indiscriminate and disproportionate attacks, for example, in the context of warnings to civilians prior to attacks (Dill; Benabbass and Zwanenburg).

Furthermore, the text of the provision itself lends support to a broader reading. The rule prohibits the acts and threats of violence “the primary purpose of which is to spread terror among the civilian population”, thus placing the emphasis on why the violence is used, rather than what is being targeted. Such a focus would be difficult to explain if the provision were only confined to acts of violence against civilians that are already unlawful, as such attacks are prohibited irrespective of their purpose. The reference to the “primary purpose” becomes meaningful precisely in situations where the underlying act of violence may be directed at a legitimate military objective, but is carried out with the primary aim of terrorising the civilian population. 

The prohibition of spreading terror among the civilian population in the context of attacks on dual-use objects 

Such reading of the provision becomes even more plausible and significant in the context of the attacks on so-called “dual-use objects” – a term often employed to describe objects that simultaneously serve civilian and military purposes (Proportionality Study, p. 37. For criticism of the use of the term in contemporary practice see Capone; Hathaway, Khan, Revkin; Proportionality Study, p. 38). Such objects will constitute legitimate military targets if they fulfill the relevant criteria of making an effective contribution to military action and offering a definite military advantage (CIHL Rule 8; API, Article 52(2)). 

In the context of attacks on dual-use objects, the prohibition of spreading terror among the civilian population acquires particular importance. While attacks on such objects may constitute attacks on legitimate military objectives, attacking them is likely to also cause civilian harm, making them especially susceptible to being instrumentalised to instil terror among the civilian population under the guise of an attack on a legitimate military target. 

However, to determine the “primary purpose” of an attack, one has to demonstrate the principal intent of the attacker, which is a particularly demanding task, especially given the circumstances of military secrecy. Moreover, it is unlikely that an attacker would state its intent to terrorise the civilian population, and it will thus have to be inferred “from the circumstances of the acts or threats, that is from their nature, manner, timing and duration” (Galić Appeal, ¶104). It is argued that in cases involving attacks on dual-use objects, such intent may be inferred when an attack causes foreseeable disproportionate harm to civilians and civilian objects and is carried out in a way that amplifies the visibility of that harm. With this in mind, the analysis now turns to assessing whether the attacks on Iran’s oil facilities exhibit such intent. 

Assessing primary intent in attacks on dual-use targets: the case of Iran’s oil facilities

When describing the strike, the IDF explained that it targeted the fuel storage complexes due to the “direct and frequent use … to operate military infrastructure”, specifically because these complexes were used “to distribute fuel to various consumers, including military entities in Iran”. The wording chosen suggests that Israel treated the facilities as dual-use objects, which were regularly used for military purposes. Provided the Israeli military had reliable information confirming such use, and that the criteria of contribution and advantage are met, the targeting of these facilities would comply with the principle of distinction.

The analysis thus turns to the principle of proportionality, which requires weighing concrete and direct military advantage against the expected incidental harm to civilians, civilian objects (CIHL, Rule 14), including the environment (CIHL, Rule 43.C; Guidelines, Rule 7; Draft Principles, Principle 14), and prohibits attacks where the expected damage outweighs the advantage. 

When conducting a proportionality assessment in relation to dual-use objects, the attacker has to consider the civilian use and function of the object in the civilian side of the proportionality assessment (Proportionality Study, pp. 37-38).  Moreover, when assessing the proportionality of an attack (and especially its effects on the environment), it is particularly important to consider the foreseeable indirect effects of the attack, i.e. the effects occurring through more than one causal step (Guidelines, para. 117; Proportionality Study, pp. 43-44; see also, Kolb, suggesting concrete criteria for such an assessment). 

Given the general explanation of Israel’s attack, cited above, one can infer that the anticipated military advantage from the attack was the disruption of the possibility of fuelling military infrastructure. The attack has indeed temporarily interrupted the distribution of fuel. However, it is unclear how long this restriction remained in place or how significantly it affected Iran’s overall fuel availability, given the country’s multiple alternative storage and refining facilities. Yet, in the days following the attack, there was no evidence suggesting that the said attacks had meaningfully interrupted Iran’s military activities. 

On the direct damage side, it has been reported that six people were killed and 20 were wounded at the sites attacked. The concrete damage to the depots has not been reported, but given the scale of the fires it caused, it likely was significant. 

Yet the main damage from the attack arose from indirect effects that were foreseeable at the time of the attack. The attacks have, foreseeably, resulted in large-scale fires and toxic smoke. Moreover, weather conditions on the day following the attack, characterised by an extratropical storm, caused the “black rain” to spread toxic pollution widely, depositing soot and oil particles over residential areas. The effects of the attacks raised concerns among health and environmental experts, highlighting that such effects will have health and environmental consequences that will last “for decades”. Moreover, the attacks led to the imposition of a 20-litre per vehicle quota on fuelling civilian cars, with certain fuel stations administering only 5 litres per car, making evacuation from Tehran particularly challenging. Based on the available information, it appears that the strikes in question have violated the proportionality principle. 

Moreover, the attack appears to have been carried out in a way that amplifies the visibility of the civilian harm. The attacks, performed on the facilities located around a 10-million-inhabitant city, lying at a high plateau surrounded by mountains, created conditions in which smoke and pollution would linger over densely populated areas, producing scenes that were described as “apocalyptic”. The prevailing meteorological conditions further intensified these effects by preventing the dispersion and generating “black rain” fallout across the city, thereby amplifying both the environmental damage and the psychological impact on the civilian population.

Finally, an important factor to consider in the present analysis is the repeated rhetoric of both the US and Israeli leaders aimed at calling the Iranian people to “take over” their government. This contextualising factor may further suggest that the attack was supposed to further exert pressure on the civilians in Tehran. 

Conclusion  

Taken together, the limited and uncertain military advantage of disrupting fuel distribution, when weighed against the extensive, foreseeable, and long-lasting civilian and environmental damage, raises serious doubts as to the compliance of the attacks in question with the principle of proportionality. Moreover, the scale, visibility, and environmental amplification of the effects, combined with the broader context of the government takeover expectations from the Iranian people, support the inference that civilian impact was not merely incidental, but may have been instrumentalised to exert psychological pressure on the population, potentially bringing the strikes within the scope of the prohibition of terrorising civilians.