Maritime Blockade and its Starvation Effect: A Key Material Element in the Crime of Genocide?
In modern terms, a maritime blockade can be defined as “a belligerent operation intended to prevent vessel traffic from all States from entering or leaving specified coastal areas that are under the sovereignty, occupation, or control of an enemy. Such areas may include ports and harbors, the entire coastline, or parts of it” (Newport Manual, para. 7.4.1). The law applicable to maritime blockade as a method of warfare has evolved over the last few hundred years in a manner quite independent of its fraternal concept of siege. As maritime capabilities in terms of persistence and presence escalated, and the trade effects of maritime blockade became effective on a much wider scale, blockade evolved from a subordinate coastal element in support of local siege operations to become an entirely separate strategic maritime lever of economic warfare. By contrast siege—as understood in the law of armed conflict (LOAC) generally—has remained a more operational and localised method of warfare on land.
Nevertheless, although the relevant law and strategy between blockade and siege has diverged, both methods still share a (relatively (p. 690-97) modern (p. 376-78)) concern with prohibitions on the starvation of the civilian population and the denial of objects essential for that civilian population’s survival.
Further, as I have indicated elsewhere, there is (in my view) a threshold at which a failure to facilitate relief, or to permit the provision of essential humanitarian supplies to the civilian population, may become independently wrongful regardless of any conditionality built into the lex lata. In relation to maritime blockade, these concerns are reflected, in the law of naval warfare (LoNW) context, by San Remo Manual Rules 102(a) and 103.
102. The declaration or establishment of a blockade is prohibited if:
(a) it has the sole purpose of starving the civilian population or denying it other objects essential for its survival …
103. If the civilian population of the blockaded territory is inadequately provided with food and other objects essential for its survival, the blockading party must provide for free passage of such foodstuffs and other essential supplies, subject to:
(a) the right to prescribe the technical arrangements, including search, under which such passage is permitted; and
(b) the condition that the distribution of such supplies shall be made under the local supervision of a Protecting Power or a humanitarian organization which offers guarantees of impartiality, such as the International Committee of the Red Cross.
A slightly narrower, but still functionally consistent, view is reflected in the Newport Manual, which asserts that “[t]he establishment of a blockade is prohibited if it is solely intended to starve the civilian population, or solely intended to deprive the civilian population of objects essential to its survival” (para. 7.4.5). And although the Newport Manual then rejects that there is an obligation to facilitate humanitarian aid shipments, it provides some mitigation of this view by then confirming that: 1) “the blockading power is prohibited from arbitrarily denying consent to a request for the provision of humanitarian relief consignments by a qualifying humanitarian organisation;” and that 2) the blockading power must not deny humanitarian relief in “exceptional circumstances in which the very survival of the civilian population is at stake and when the authorities of the blockaded area are incapable of providing such goods or to have them provided” (para 7.4.5).
Of note, the U.S. Department of Defence Law of War Manual similarly asserts that the law applicable to starvation in maritime blockade is that which applies on shore (see § 5.20, 13.10.2.4, & 17.9.2) and that “[s]tarvation of civilians as a method of combat is prohibited.”
Two things can be distilled from the agreement between the broader (San Remo Manual) and narrower (Newport Manual) views on this issue of starvation as an effect of maritime blockade. First, given the harshness of the “sole purpose” criterion, if a widespread consequence of civilian starvation nevertheless arises from the implementation of a blockade, then it must be mitigated by the accompanying relief shipments permission obligation.
However, this obligation is a conditional one, requiring that the blockading power allow and make arrangements for the necessary humanitarian aid to enter the blockaded territory, whilst acknowledging that where the effectiveness of these measures is then frustrated by the territorial power (e.g., that power diverts the facilitated food aid to its military forces), then the blockading power may not, as a matter of law, necessarily be responsible for that starvation outcome.
The second point on which the San Remo Manual and Newport Manual also appear to agree is that the relief shipments obligation becomes iteratively more acute and onerous as the starvation consequence approaches an “existential” level.
If we are to then consider the causal nexus between blockade and starvation on one hand, and starvation and genocide on the other, this then raises the question as to whether a maritime blockade linked to such a starvation consequence could itself qualify as a genocidal act. It would seem obvious that it could, and that the causal chain is readily apparent. However, it is at this point that the issue of siege once again complicates the relationship with the maritime act. Enforcing a blockade creates consequences ashore, where it is possible to see starvation as an incident of genocide. This issue requires some unpacking.
Untangling the Legal Intersection between Blockade, Starvation, and the Prohibition of Genocide
As a matter of black letter law, there can be no doubt that a maritime blockade is prohibited by the 1948 Genocide Convention if it is part of an act, acts, or a plan “committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group, … ” by inter alia, “[d]eliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part” (art. II(c)). Starvation need not be the “sole purpose” of the blockade.
This conclusion is legally sound for many reasons, of which the most powerful is likely that the prohibition on genocide is both a customary (International Court of Justice (ICJ), Reservations to the Genocide Convention advisory opinion (1951) p. 15, 23) and treaty-based rule, and is broadly considered a rule of jus cogens (ICJ, Bosnia Genocide (2007), p.61). Equally clearly, the 1977 Additional Protocol I (AP I) Article 49(3) limitations on the applicability of certain sections of that treaty to the law of naval warfare (LoNW) can not apply to genocide. Furthermore, the crime of genocide at Article I of the 1949 Genocide Convention and at Article 6 of the Rome Statute of the International Criminal Court also clearly reflects its applicability both within and outside of contexts governed by LOAC (and LoNW), again indicating its (logically) broad ambit of applicability. Thus, a maritime blockade that creates starvation (or, indeed, denial of access to objects indispensable to the survival of the civilian population) may, in an objective sense, be an incident of genocide regardless of the “sole purpose” criterion reflected in the lex specialis of the law of blockade.
This is not to say, however, that proving the (non-sole purpose) starvation effect of an otherwise lawful blockade is nevertheless unlawful, because it is an incident of genocide, would necessarily be simple. As the ICJ declared in the 2007 Bosnia Genocide case, not only do the proofs of the crime require a mental element (“intended,” “deliberate”) but also,
… the establishment of the ‘intent to destroy, in whole or in part, … [the protected] group, as such.’ It is not enough to establish … that deliberate unlawful killings of members of the group have occurred. The additional intent must also be established, and is defined very precisely. … The acts listed in Article II [of the Genocide Convention] must be done with intent to destroy the group as such in whole or in part (p. 186-87).
Furthermore, “The specific intent is also to be distinguished from other reasons or motives the perpetrator may have. Great care must be taken in finding in the facts a sufficiently clear manifestation of that intent” (p. 189). For findings in a contentious case, as the ICJ has noted in the 2024 Occupied Palestinian Territory advisory opinion, it would thus be “necessary for the Court to make findings of fact with regard to specific incidents allegedly in violation of international law” (p. 77).
That is, if it cannot be proven that the blockade was implemented with the specific intent of creating the genocidal conditions, then it may be that it is not the blockade that is the causal attendant of the genocide by starvation. The material cause may instead lie in the intervening operations, checking and transhipment, that stand between the landing of food and items indispensable to the survival of the civilian population and their entry into the blockaded territory, as with the Gaza maritime blockade. This means that it would be the specific genocidal intention behind the policy of relief shipment frustration—adopted after the blockade is no longer the centrally relevant and animating method of warfare, when the aid has been delivered to shore for checking before transhipment into the blockaded territory—that is the materially and legally relevant fact. And it is upon exactly this fact situation that there appears to be some emerging but perhaps accidental and unintended practice.
The Gaza Arrest Warrants
What do the Gaza starvation arrest warrants indicate about situations where the time- and law-defined consequences of a maritime blockade end, and some other method of warfare or operational practice becomes the key legal and factual element? As I have argued previously, one example of the difficulties that might be encountered in the inclusion of a maritime blockade as part of the fact and intention matrix for the Rome Statute Article 8(2)(b)(xxv) offence of starvation as a method of warfare against civilians, or denial of objects indispensable to the survival of the civilian population, is perhaps evident in the war crimes arrest warrant against Binyamin Netanyahu in respect of Gaza. The International Criminal Court (ICC) Prosecutor explained on 20 May 2024 that the starvation offence (amongst others),
… occurred through the imposition of a total siege over Gaza that involved completely closing the three border crossing points, Rafah, Kerem Shalom and Erez, from 8 October 2023 for extended periods and then by arbitrarily restricting the transfer of essential supplies – including food and medicine – through the border crossings after they were reopened. The siege also included cutting off cross-border water pipelines from Israel to Gaza – Gazans’ principal source of clean water – for a prolonged period beginning 9 October 2023, and cutting off and hindering electricity supplies from at least 8 October 2023 until today.
That is, there is mention of siege and land crossings, but no mention of the maritime blockade in the context of the starvation allegation. On one hand, this may be a conscious exclusion because the blockade is considered to have complied with the lex lata in terms of setting in place mechanisms for checking and delivering relief shipments via allocated Israeli ports, and that it was then the land-based siege law that was breached when the relief shipments were not delivered in an adequate or timely manner. This would be consistent with the Report of the Secretary-General’s Panel of Inquiry on the 31 May 2010 Flotilla Incident (the “Palmer Report’’), which assessed that,
The naval blockade is often discussed in tandem with the Israeli restrictions on the land crossings to Gaza. However, in the Panel’s view, these are in fact two distinct concepts which require different treatment and analysis … the naval blockade as a distinct legal measure was imposed primarily to enable a legally sound basis for Israel to exert control over ships attempting to reach Gaza with weapons and related goods. This was in reaction to certain incidents when vessels had reached Gaza via sea. We therefore treat the naval blockade as separate and distinct from the controls at the land crossings. This is not to overlook that there may be potential overlaps in the effects of the naval blockade and the land crossings policy (p. 70).
On the other hand, the Arrest Warrants reference to “siege” may implicitly include the maritime blockade, although the reference to the land border crossings appears to be quite explicit. The ICC Office ofthe Prosecutor’s commissioned Report of the Panel of Experts likewise refers to “a siege on the Gaza Strip and the closure of border crossings; arbitrary restrictions on entry and distribution of essential supplies; cutting off supplies of electricity and water, and severely restricting food, medicine and fuel supplies” (p. 28).
The term “blockade” is not used, and it is unclear if the maritime blockade was considered by the Panel to simply be a component of the “siege” or the “restrictions on entry,” or (alternately) was not considered by the Panel to form part of the fact matrix underpinning this allegation. This said, it is certainly possible that the Panel’s implicit view is that the blockade, although lawfully instituted, is nevertheless unlawfully conducted precisely because its effects (diversion of aid to shore for inspection and transhipment) are facilitative of the ultimate consequence.
Nevertheless, and regardless of how the ICC ultimately deals with this question of blockade “culpability” in this specific case, it is clear, to me at any rate, that the applicable lex lata provides that a maritime blockade which is a component of a crime of genocide is by definition independently unlawful ab initio. But to be relevant as a component of this crime, the blockade itself must be intentionally directed to that purpose.
The challenge, therefore, is working out whether a blockade is in fact an express component of the relevant alleged genocidal policy, or whether the blockade is valid, and it is the subsequent conduct ashore that is the “start point” for consideration of the fact-law-context matrix for assessing whether the conduct is related to a genocidal policy. That is, it is not the (otherwise lawful) maritime blockade that is the start point of the genocide assessment. Rather, the start point for assessment is if/when the diverted and landed aid (which is a lawful end point for a blockade, when not employed as a component of genocide) is subsequently subjected to: 1) an intentional failure to tranship, or prevention of transhipment, across the land borders into the besieged territory (a LOAC issue, not a LoNW blockade issue); or 2) the intentional frustration of distribution once the aid has entered the destined besieged territory (again, a LOAC issue rather than a LoNW blockade issue).
This then raises the question of whether there are any circumstances where it is the maritime blockade itself which could and should be the start point for the assessment of intention and conduct in respect of a starvation objective as a component of a genocidal policy. I think that there is indeed one situation where this might be the case: a maritime blockade of a small island State.
Can a Maritime Blockade Cause Starvation with or without Genocidal Intent?
The short answer is yes. First, it is theoretically possible that a small island State (e.g., Mauritius, Seychelles, Maldives in the Indian Ocean; any of the small island States in the Pacific; Cape Verde in the Atlantic Ocean) could be subject to a maritime blockade that created a starvation consequence. It is also possible that larger islands such as Taiwan could also be subject to a starvation-inducing blockade if the blockading State possesses forces large and capable enough to enforce the blockade.
Such States are acutely vulnerable, as a straight-forward matter of geography, to maritime blockade precisely because there is no alternative access point for food or other items essential to the survival of the civilian population. Furthermore, there is no option for diversion to a land border for checking and transhipment which would than “land-ise” the aid and transform the operation into a LOAC siege, thus removing the maritime blockade from first order consideration in terms of the fact-law-context matrix required to prove the starvation objective.
Second, as to whether this starvation consequence could be the key material fact in an allegation of genocide, again the answer is yes. The fact of such a starvation objective could, in the case of small island States, clearly constitute genocidal intent because the definition of the crime includes “destruction of a … national group… as such.” It seems clear that, as a matter of lex lata, it would indeed be possible that a maritime blockade with the objective (even if not the sole objective) of starving the civilian population of a small island State, could form the key material fact in a genocide indictment, if that starvation was intended to destroy in part or in whole, the targeted national group.
Conclusion
The potential for a maritime blockade to be lawful, but for the shore-based steps subsequent to (permissible) diversion of food and objects indispensable to the survival of the civilian population for inspection, and then transhipment into the destined territory for the civilian population, to be unlawfully frustrated, is abundantly clear. The implication, of course, is that any assessment of a starvation/denial objective in terms of being a constituent component of a policy of genocide would thus begin where the illegality begins, that is, once the aid has been landed after diversion.
Or put another way, as the Gaza arrest warrants seem to indicate, where there is maritime blockade that leads to diverted aid then being subject to the law of siege, the illegality of any siege operation—and its consequences of starvation and potentially genocide—do not impugn the independent lawfulness of the blockade itself. This seems to be the implication in the references to siege, but not blockade, as the context of illegality in the Gaza arrest warrants.
This said, however, it is entirely possible that the Gaza ICC cases, if they proceed to trial, may take a different approach and commence assessment of any starvation objective with the maritime blockade rather than from the later in time point at which the aid was landed and then subject to the law of siege, whereupon any policy of delivery frustration would then become material. The approach ultimately taken will thus have significant implications for assessing any charges of genocide. However, where the only access point to a territory is by sea (whether by aircraft or by ship), as is the case with small island States, then it is the maritime blockade that properly becomes the start-point for assessing any starvation objective, and thus any potential policy of genocide against a national group.
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Rob McLaughlin is Professor of International Law at the Australian National Centre for Ocean Resources and Security, Honorary Professor at ANU, and a Senior Fellow at the Stockton Centre for International Law at the US Naval War College.
The views expressed are those of the author, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.
Photo credit: Israel Defense Forces
