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By Professor Iain Scobbie, School of Oriental and African Studies:


A Note to the Reader
Bullet Points
I. The “normal” situation: exclusive flag-State jurisdiction
II. The armed conflict paradigm:
III. The law of blockade:
IV. Israel’s blockade of Gaza:
V. Interception of vessels attempting to breach the blockade:
VI. Reviving more of the past?

A Note to the Reader:
This is not a polished paper, nor is it in its final form(s). Rather it sets out what I think are the principal legal issues involved in Israel’s blockade of Gaza and interception of vessels running the blockade in order to deliver humanitarian aid. This paper is being sent out for comment, as the law of naval warfare is a fairly specialised area which, on the whole, has not received as much attention in recent years as the law of armed conflict on land from States in terms of the formulation of treaties. The principal contemporary document is the San Remo Manual, adopted in 1994, which was drafted by a team of international lawyers and naval experts convened by the International Institute of Humanitarian Law. The normative weight of this Manual is discussed below. The issues raised by the blockade and interception of vessels are complex: to some extent, this is because the relevant law is drawn from different periods of international law. The law of naval warfare, in its classic form, was developed before the Covenant of the League of Nations placed initial restrictions on resort to war, and before the United Nations Charter prohibited the use of force in international relations, except in self-defence or as a matter of collective security authorised by the UN Security Council under Chapter VII of the Charter. The changing normative background has to be borne in mind when evaluating the continued relevance of older instruments which regulated the law of maritime warfare. As this is not the final version of my thoughts on these matters, this paper is not for quotation.

And the bullet points are:

  • As a general rule, the flag State of a ship has exclusive jurisdiction over it when it is on the high seas, and consequently other States cannot interfere with it;
  • Israel has justified its interception of vessels on the basis of the maritime blockade it declared over Gazan offshore waters in January 2009: this is a blockade in the technical legal sense which must be distinguished from terrestrial import restrictions which are more akin to a siege. This analysis deals only with the maritime blockade;
  • Given Israel’s reliance on the law of blockade (and thus the law of naval warfare), the legal framework for analysis of the blockade and interception of the Mavi Marama flotilla and Rachel Corrie can only be the law of armed conflict, and not a paradigm based on law-enforcement or police action;
  • This is the legal framework Israel itself has invoked, given its reliance on the San Remo Manual on international law applicable to armed conflicts at sea: this instrument is not legally binding upon States, but it is regarded as authoritative. It is, however, not comprehensive and needs to be supplemented by other instruments in order to fill gaps or provide interpretative guidance;
  • Israel claims that it is engaged in an “armed conflict” with Hamas, but has remained ambiguous on whether it regards this conflict as an international armed conflict or as a non-international armed conflict: the classification is important as different rules apply to each, in particular in relation to the supply of humanitarian aid;
  • If Israel remains the occupant of Gaza for the purposes of the law of armed conflict, then the conflict should be classified as an international armed conflict. Israel claims that, as a result of its disengagement from Gaza in 2005, it is no longer the occupant: this is not the consensus of scholarly commentary;
  • The declaration of a blockade by a State when it is involved in a conflict with a non-State actor is a recognition by that State that the conflict is an international armed conflict;
  • A blockade is the imposition of a comprehensive prohibition of trading with the enemy by the merchant vessels of third/neutral States. It is not merely a prohibition on trade in contraband—that is, in goods destined for the enemy territory which may be used in armed conflict. A blockade entails a complete prohibition in trade of any kind;
  • A blockade is only lawful if it is declared; it is effective; and it is impartial (that is, if it applies to vessels of all nationalities, including vessels of the blockading State and its allies): otherwise it is a legal nullity (it does not exist);
  • Blockades may legitimately be enforced on the high seas; one might expect that the area of operations of Israeli forces enforcing the blockade should be close to the Gaza coastline given its control of Gazan offshore areas and the lack of a credible threat from onshore forces or installations;
  • The lawful capture of a vessel attempting to breach a blockade requires that the blockade be lawful in the first place;
  • A blockade is a legal nullity if imposed against the coastline of enemy territory occupied by the blockading State;
  • A blockade is unlawful if it has the sole purpose of starving the civilian population of the blockaded territory, or if the damage to the civilian population is excessive in relation to the military advantage anticipated from the blockade;
  • It is difficult to argue that the sole aim of the blockade is to starve the civilian population of Gaza, as it is only one aspect of the restrictions placed by Israel upon imports to Gaza which are aimed at preventing the infiltration of arms and ammunition to Hamas;
  • The effects of the blockade on the civilian population might be seen as excessive in relation to its aim of preventing the infiltration of arms and ammunition, as this could be achieved by the lesser measure of Israel’s naval forces searching vessels bound for Gaza for contraband; if so, the blockade’s excessive effects would render it unlawful;
  • The provisions of the San Remo Manual place an obligation on the blockading power to allow humanitarian aid pass through the blockade if the civilian population is inadequately supplied with food, medicine and other essential supplies: vessels carrying humanitarian aid are subject to search by the blockading power;
  • These requirements parallel obligations placed on an occupant by Geneva Convention IV: an occupant has the duty to ensure that the food and medical supplies are made available to the civilian population, and that its material conditions are maintained at reasonable level—this is in contrast to the level of “basic humanitarian needs” applied by Israel to Gaza;
  • Geneva Convention IV also places an “unconditional obligation” on an occupant to allow the transit of humanitarian relief into territory it occupies from third States and impartial humanitarian organisations; these relief consignments are subject to search by the occupant;
  • Consequently, Israel is under an obligation to allow the entry of relief consignments into Gaza under both the law of maritime warfare and the law of occupation;
  • If a blockade is lawful, then the blockading State is entitled to prevent vessels breaching it, but vessels running the blockade are under no duty to stop: they can resist capture or attempt to escape—but in that case, they are liable to attack by the warships of the blockading State, but that attack must not be excessive in relation to its anticipated military advantage;
  • If a blockade is unlawful, either because it was never validly established or maintained, or was established against territory occupied by the blockading power, or has become unlawful because of the adverse consequences it has on the welfare of the civilian population, then legally it does not exist: consequently, it is unlawful for the “blockading” State to attempt to enforce it against vessels of other States on the high seas—this could amount to a use of armed force contrary to Article 2.4 of the UN Charter. If enforcement were attempted, then the crew and passengers of the intercepted vessel would possess the personal right to self-defence within the modalities allowed by the domestic law of the flag State;
  • And finally, just as the law of blockade has rarely been used since the close of World War Two, Protecting Powers, whose function is to supervise the lawful conduct of an armed conflict, have rarely been appointed. Their appointment could lead to an impartial and authoritative assessment of matters such as the need for humanitarian assistance in Gaza.


I. The “normal” situation: exclusive flag-State jurisdiction

In normal circumstances, ships on the high seas are under the exclusive jurisdiction of the State whose flag they fly. The basic principle under customary international law was set out by the Permanent Court of International Justice in the Lotus case (1927):

failing the existence of a permissive rule to the contrary,

[a State] may not exercise its power in any form in the territory of another State. In this sense jurisdiction is certainly territorial; it cannot be exercised by a State outside its territory except by virtue of a permissive rule derived from international custom or from a convention…

…vessels on the high seas are subject to no authority except that of the State whose flag they fly. In virtue of the principle of the freedom of the seas, that is to say, the absence of any territorial sovereignty upon the high seas, no State may exercise any kind of jurisdiction over foreign vessels upon them. Thus, if a war vessel, happening to be at the spot where a collision occurs between a vessel flying its flag and a foreign vessel, were to send on board the latter an officer to make investigations or to take evidence, such an act would undoubtedly be contrary to international law.

…A corollary of the principle of the freedom of the seas is that a ship on the high seas is assimilated to the territory of the State of the flag of which it flies, for, just as in its own territory, that State exercises its authority upon it, and no other State may do so. [1]

International law does provide that warships may interfere with the passage on the high seas of ships flying the flag of another State in limited circumstances. Article 22.1 of the 1958 Geneva High Seas Convention (which sets out customary international law,[2] and to which Israel is a party):

Except where acts of interference derive from powers conferred by treaty, a warship which encounters a foreign merchant ship on the high seas is not justified in boarding her unless there is a reasonable ground for suspecting:

a. that the ship is engaged in piracy; or
b. that the ship is engaged in the slave trade; or
c. that, though flying a foreign flag or refusing to show its flag, the ship is, in reality, of the same nationality as the warship.

This Article was repeated in Article 110.1 of the 1982 United Nations Convention on the Law of the Sea, to which Israel is not a party. These exceptions are not relevant to the matter in hand.

Because the vessels were intercepted on the high seas, beyond the limits of Israel’s territorial sea, these interceptions cannot be classified as law enforcement (or police) action. This is not affected by the terms of the 1995 Israeli-Palestinian Interim Agreement on the West Bank and the Gaza Strip which provides, in Article XII, that Israel has the responsibility for “defence against external threats from the sea”: further, as the UN Office for the Coordination of Humanitarian Affairs notes, Israeli naval forces restrict fishing beyond three nautical miles from the Gazan shore, and often at a lesser distance.[3] Law enforcement on the high seas by one State on vessels flying the flag of another is unlawful. Law enforcement is the assertion of jurisdiction by a State: as the flag State has exclusive jurisdiction over vessels on the high seas, this precludes the lawful assertion of another State’s jurisdiction on these vessels in the absence of an agreement between the States involved, or where one of the exceptions recognised in the law of the sea conventions is applicable.

The legal framework for the analysis of Israel’s blockade[4] of Gaza, and the resultant interceptions of vessels, can only be the law of armed conflict. This is indeed mandated by the undisputed facts of the interceptions: the vessels were attempting to breach a blockade. The declaration of a blockade is, in itself, a belligerent act. As Article 7.7.1 of the US Commander’s Handbook on the Law of Naval Operations[5] states:

Blockade is a belligerent operation to prevent vessels and/or aircraft of all nations, enemy as well as neutral, from entering or exiting specified ports, airfields, or coastal areas belonging to, occupied by, or under the control of an enemy nation. While the belligerent right of visit and search is designed to interdict the flow of contraband goods, the belligerent right of blockade is intended to prevent vessels and aircraft, regardless of their cargo, from crossing an established and publicized cordon separating the enemy from international waters and/or airspace.

The law of armed conflict provides the State with a more permissive regime for the evaluation of its actions than would be the case if the situation were one of law enforcement. In the latter case, presumably the framework for evaluation would be the more stringent requirements of human rights law-as illustrated, for instance, by the naval actions to repress piracy off the coast of East Africa.[6]

II. The armed conflict paradigm:

A blockade may be imposed by a party to an armed conflict, or be mandated by the UN Security Council acting under Chapter VII of the UN Charter as a response to a threat or breach of international peace, or an act of aggression. This would require the Security Council to take a decision declaring a blockade, binding on all UN members, acting under Article 42 of the UN Charter, which provides:

Should the Security Council consider that measures provided for in Article 41 [ie, measures not employing the use of armed force] would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action my include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations.

The express reference to blockade in Article 42 was one reason why the majority of the group of experts convened by the International Institute of Humanitarian Law thought that blockade remained a viable method of warfare.[7]

Israel claims that it relinquished control over Gaza as the result of the implementation of its 2005 disengagement plan, and accordingly is no longer the occupant of the territory. Nevertheless, it claims that there exists a state of armed conflict between it and Hamas. This position was endorsed by Israel’s Supreme Court, sitting as the High Court of Justice, in January 2008 in Jaber al Bassouini Ahmed et al v Prime Minister and Minister of Defense.[8] The existence of an armed conflict was reiterated in a briefing paper on the legal aspects of Operation Sea Breeze issued by the Military Strategic Information Section of the Israel Defense Forces. The classification placed on this conflict is ambiguous: both the Jaber al Bassouini Ahmed case and the Operation Sea Breeze briefing paper refer only to an “armed conflict” without clarifying whether it is an international or a non-international armed conflict. The precise classification is important because different instruments and rules apply to these different types of conflict. Of particular note is that different rules apply in relation to the obligation to provide humanitarian relief to the civilian population.

Although Israel claims that it is no longer the occupant of Gaza, because of its control of Gaza’s land and maritime borders, its control of Gazan airspace, and its ability to intervene forcibly at will in Gaza, this claim is not accepted by the majority of commentators.[9] If the occupation subsists, then this in itself would be sufficient to classify the situation as one of international armed conflict. Regardless of this consideration, the declaration of the blockade by Israel on 6 January 2009,[10] during the course of Operation Cast Lead, is conclusive. While Gaza, as an integral part of the occupied Palestinian territories, is not a State, a clear analogy may be drawn with the declaration of a blockade during a civil war. If the government of a State proclaims a blockade in relation to territory occupied by insurgent forces, this amounts to a recognition of the belligerent status of those forces, and thus the conflict is classified as an international armed conflict. Even if a blockade fails to meet the legal requirements of a valid blockade, and thus is a legal nullity, the recognition of belligerency arising from its declaration subsists: the conflict thus remains classified as an international armed conflict.[11] Accordingly, whether as a matter of occupation or of recognition of belligerency, the armed conflict between Israel and Hamas should be seen as one which calls for the application of the laws pertaining to an international armed conflict.[12]

III. The law of blockade:

a. The sources of the law:

In its justification of the blockade and interception of vessels, Israel has relied, inter alia, on the San Remo Manual on International Law applicable to Armed Conflicts at Sea. The San Remo Manual is not an official document produced by States, but rather was produced by a private body, the International Institute of Humanitarian Law. It is expressly stated to be a restatement of customary international law, but one which also contains an element of progressive development of the law.[13] As an unofficial document, the Manual is not formally binding on States, although inasmuch as its content restates customary international law it is an expression of existing law. The San Remo Manual has undoubtedly been influential: for example, much of the chapter on maritime warfare in the UK Manual of the law of armed conflict “reflects its content”:

When appropriate and possible the text of the San Remo Manual has been repeated in this chapter. However, where necessary the wording used in this chapter departs from the precise San Remo text either because that text does not reflect United Kingdom practice or because the San Remo text requires clarification or amplification.[14]

The UK Manual also notes that some treaties, mainly from the early twentieth century, may continue to be relevant, and that several principles contained in treaties which regulate land warfare constitute rules of customary international law which are also applicable to maritime warfare.[15] Further, the UK Manual cautions that:

In considering the rules set out in this chapter, it is necessary to bear in mind at all times one point of central importance, namely that the conduct of armed conflict at sea is subject to the limitations imposed by the UN Charter on all use of force. One particularly important aspect of those limitations is that even when resort to force is justified, it should not exceed what is necessary and proportionate to the achievement of the goal for which force may be used. In a conflict of limited scope, this may mean that a belligerent state is constrained, to a greater extent than the rules set out in the present chapter might suggest, in the action that it may lawfully take against the shipping or aircraft of states not involved in the conflict.[16]

Accordingly, the San Remo Manual is not comprehensive, and earlier instruments retain utility in filling gaps in it or as an aid to the interpretation of its provisions -although these must be read in the light of subsequent developments, such as the UN Charter, the 1949 Geneva Conventions (particularly Convention II which deals with the “amelioration of the condition of wounded, sick and shipwrecked members of armed forces at sea”),[17] and the 2005 restatement of customary international humanitarian law undertaken by the International Committee of the Red Cross.[18] Two instruments appear to be particularly useful in this regard, namely the 1909 Protocol of the London Naval Conference [19] and the 1939 Harvard Draft. The preliminary provision of the 1909 Protocol states that its signatories were agreed that “the rules contained in the following Chapters correspond in substance with the generally recognised principles of international law”. In contrast, the Harvard Draft is the work of a private organisation which, like the San Remo Manual, sought to codify existing law while engaging in a degree of progressive development.

A final consideration to bear in mind arises from the UK Manual’s comment that in a conflict of limited scope, a belligerent State might find itself more constrained than the text of its provisions indicate. Daniel O’Connell, an influential commentator on the law of the sea and the conduct of naval operations, was of the opinion that in a limited conflict (in terms of the parties involved and its geographical scope), hostile actions should be confined to the territorial seas of the belligerents (which is a 12 nautical mile maritime zone projected the coast, and subject to the coastal State’s sovereignty) or, at the very most, to their contiguous zones (which extends 24 nautical miles from the coast). He argued that limited wars must not escape the territories of the parties to the conflict, and must not be carried into the high seas where international interests would be directly engaged. O’Connell claimed that in conflicts in the Middle East, there was a general understanding that hostilities should not extend beyond the territorial sea: on the basis of the Eilat incident in October 1967 he thought that this was treated as, or was tantamount to, a legal rule.[20] It must be conceded that as O’Connell died in 1979, his views did not take account of subsequent practice in, for example, the Falklands conflict (1982) and the Iran-Iraq war (1980-1888) where the belligerents declared maritime exclusion zones. Exclusion zones, however, raise different legal questions than blockades—“blockade law is inapplicable to the concept of exclusion zones”.[21]

b. The basic content of the law of blockade:

The purpose of a blockade is to impose a comprehensive prohibition of trading by neutral States with the enemy. It does not target any particular cargo as contraband—that is “goods which are ultimately destined for territory under the control of the enemy and which may be susceptible for use in armed conflict” [22] —but operates to exclude all transit into and out of a defined area or location. A belligerent, however, cannot gain the advantages of blockade without complying with the legal conditions for its establishment.[23] The basic requirements for a lawful blockade is that it must be declared, impartial and effective. Articles 93 and 94 of the San Remo Manual provide:

93. A blockade shall be declared and notified to all belligerents and neutral States.

94. The declaration shall specify the commencement, duration, location, and extent of the blockade and the period within which vessels of neutral States may leave the blockaded coastline.

Article 95 states that the blockade must be effective, which is a question of fact. The UK Manual augments the San Remo text by providing:

The question whether a blockade is effective is a question of fact, and is of significance because of the need to distinguish between legitimate blockading activity and other activities (including visit and search) that might be carried on illegitimately on the high seas under the guise of blockade.[24]

On effectiveness, Article of the US Commander’s Handbook states that this requires that the blockade be “maintained by a surface, air, or subsurface force or other legitimate methods and means of warfare that is sufficient to render ingress or egress of the blockaded area dangerous”. This does not “require that every possible avenue of approach to the blockaded area be covered”.[25] Both the San Remo and UK Manuals provide that the distance from the blockaded coastline at which the force maintaining the blockade may be stationed is to be determined by military requirements.[26]

The condition of impartiality entails that the blockade must be applied impartially to the vessels of all States.[27] Article of the US Commander’s Handbook notes that if the blockading belligerent discriminates in favour of or against the vessels of particular States, including its own or those of its allies, this renders the blockade legally invalid. The 1939 Harvard Draft comments that, except in cases of distress, if a belligerent licences or knowingly permits its own or any other vessels to pass through the blockade, then the blockade is regarded as raised. It states that this is an established rule: partiality in the administration of a blockade raises the blockade, although it concedes that some commentators argue that the granting of minor exceptions to the blockade for special purposes does not invalidate it. The aim of the requirement of impartiality is to prevent belligerents using blockades as pretexts for furthering their own trade with the blockaded territory at the expense of neutral States.[28]

c. the extent of blockade:

As noted above, the distance from the blockaded coastline at which the forces maintaining the blockade are to be stationed is to be determined by military requirements. In traditional law, and in principle in contemporary law, blockades may be enforced on the high seas.

At the time of the 1908-1909 London Conference, there was a perceived difference of views between Britain and the United States on the one hand, and continental European naval powers on the other, regarding when a vessel attempting to breach a blockade could be intercepted. The British/US view was that a vessel sailing towards a blockaded port with knowledge of the blockade, was liable to interception and capture from the time of it left port, however distant this was from the blockaded coast. The European view was that a vessel could only be intercepted when it attempted to cross the actual line of blockade. The instructions issued to British delegates to the London Conference noted that this divergence had given rise to distorted arguments and stated that, in practical operation, there was not much between the two positions. An examination of British prize court decisions demonstrated that, although Britain maintained in theory the principle that interception could occur at any point of the voyage, there was no case in which a vessel had been captured for breach of blockade except when it was actually close to, or directly approaching, the blockaded coastline, and that a provision should be adopted which expressed this common principle.[29] Article 17 of the London Protocol accordingly provided:

Neutral vessels may not be captured for breach of blockade except within the area of operations of the warships detailed to render the blockade effective.

This notion of the area of operations reflected the French doctrine of le rayon d’action, namely the area in which a blockading force may be stationed which ensures that it is reasonably secure from attack from the blockaded coast. The British Instructions noted that this could be a considerable distance, and at the London Conference, the United States delegation noted it could be as far as 480 miles from the coast, but in any event, the rayon d’action should not extend more than 1000 miles from the blockaded coastline.[30] Practice during World Wars One and Two which asserted the existence of “long distance blockades” are not thought to have altered the requirement that interception should be relatively close to the blockaded coastline, rather than on the other side of an ocean, because the long distance blockades were justified on the basis of reprisal—that is, that these were justified as unlawful acts taken as a response to a prior unlawful act by the opposing belligerent.[31]

The requirement in the San Remo Manual that the stationing of blockading forces be determined by military requirements “reflects the concern which the blockading power may have with respect to operations within the range of coastal armaments, aircraft or submarines of the opposing belligerent”.[32] Accordingly, it may also be seen to reflect the notion of rayon d’action embodied in the London Protocol, and principally be regarded as a concern for force protection. If this is then coupled with the notion of limited warfare, and with O’Connell’s suggestion that such hostilities should be confined to the territorial sea, then the rayon d’action of the Israeli blockade may be seen as particularly circumscribed, especially given Israel’s responsibility for security in Gaza’s offshore areas, the exclusion of Gazan vessels from maritime areas over three miles from the coast, and the lack of any credible threat to its naval forces emanating from Gaza.

IV. Israel’s blockade of Gaza:

In Tatem v Gamboa, Goddard J stated that a capture of a vessel running a blockade meant lawful capture, but that this presupposed the blockade was lawful in the first place.[33] There is authority to argue that the blockade imposed by Israel on 6 January 2009 was not legally operative when it intercepted vessels seeking to breach the blockade in the week beginning 21 May 2010 because it was a legal nullity from the outset. While it is accepted that, as matter of law, a belligerent may blockade not only the coasts of its opponent, but also the coasts of territory its opponent occupies, it is doubtful if it may institute a blockade of the coasts of territory it occupies itself.[34] Although the authority for this proposition dates from the late nineteenth/early twentieth century, it may be argued that this prohibition is strengthened by subsequent developments in the law of armed conflict regarding an occupant’s duty to provide humanitarian relief to the population of occupied territories. If it is accepted that Israel remains the occupant of Gaza, then no lawful blockade ever existed.

When Israel increased restrictions on imports into Gaza in 2006, Dov Weisglass, an adviser to Israel’s then-Prime Minister Ehud Olmert, stated “The idea is to put the Palestinians on a diet, but not to make them die of hunger”.[35] In April 2010, the UN Office for Humanitarian Affairs reported that living conditions in Gaza continue to deteriorate, principally as a result of the Israeli import restrictions. A new poverty survey conducted by UNRWA showed that the number of Palestine refugees completely unable to secure access to food and lacking the means to purchase even the most basic items, such as soap, school stationary and safe drinking water, and thus who are living in “abject poverty”, has tripled since June 2007. According to UNRWA’s findings, approximately 300 000 of its total caseload of 700 000 Palestine refugees now live in conditions of abject poverty, an increase from 100 000 in early 2007.[36] In dealing with the issue of humanitarian relief, there are layers of over-lapping law: the matter is addressed by the general law of armed conflict, by the law of naval warfare, and by the law regulating belligerent occupation. The different provisions, however, all point in the same direction: adversely affected civilian populations have a right to humanitarian relief which belligerents have the duty to facilitate.

It is perhaps appropriate to deal first with the law of naval warfare, as this is embodied in the San Remo Manual, because that is the instrument which Israel has invoked to justify its blockade and interception operations. Its reliance on the San Remo Manual has, however, been selective. Article 102 provides:

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; or
b. the damage to the civilian population is, or is expected to be, excessive in relation to the concrete and direct military advantage anticipated from the blockade.

This Article reflects Article 54.1 of Additional Protocol I which prohibits the starvation of civilians as a method of warfare. As the imposition of a blockade is a belligerent act, it must comply with the law of armed conflict. The ICRC Commentary to this provision states that “starvation” is used in its ordinary meaning, namely causing the population to suffer hunger by depriving it of its sources of food or supplies, or to “keep [it] scantily supplied with food”.[37] In other words, it extends to imposing a “diet” on the population. Although Israel is not a party to Additional Protocol I, this prohibition is a rule of customary international law which is applicable in both international and non-international conflicts.[38]

It must be borne in mind that the maritime blockade is only one facet of the restrictive measures placed on Gaza. On 19 September 2007, Israel’s Ministerial Committee on National Security Issues adopted a decision which provided in part:

The Hamas organization is a terrorist organization which has taken over the Gaza Strip and turned it into hostile territory. This organization carries out acts of hostility against the State of Israel and its citizens, and the responsibility for such acts lies with it. In light of that, it is resolved to adopt the recommendations presented by the security agencies, including continuation of the military and preventative activity against the terrorist organizations. Furthermore, additional restrictions will be placed upon the Hamas regime, in a way that will limit the passage of goods to the Gaza Strip and reduce of the supply of fuel and electricity, and there will be restrictions placed upon the movement of persons to and from the strip.[39]

Israel argues that these restrictive measures are necessary to limit rocket attacks from Gaza on southern Israel and to prevent Hamas obtaining additional weapons.

The cumulation of the measures restricting imports into Gaza by land and sea, and not simply the impact of the maritime blockade itself, has caused the deterioration of living conditions in Gaza. The maritime blockade is undoubtedly a contributing factor in the decline of living standards within Gaza, but it could be difficult to argue that its consequences as such, when viewed in isolation, are sufficient to taint the maritime blockade with illegality on the ground that its sole purpose is to starve the civilian population.

On the other hand, as the blockade is a belligerent act, it must be proportionate to its anticipated military advantage. In rejecting a petition which sought to obtain a declaration that Israel lacked jurisdiction to intercept the Mavi Marama flotilla on 31 May 2010 , President Beinisch of the Israeli High Court stated:

In light of Hamas’ control of the Gaza Strip, Israel has take various steps meant to prevent direct access to the Gaza Strip, including the imposition of a naval blockade on the Strip, which, according to the State’s declaration, is meant to block the infiltration of weapons and ammunition into Hamas ranks which have carried out shooting and terrorist attacks in Israeli territory for years with the goal of harming civilians.[40]

This aim, the interdiction of arms and ammunition, could be achieved through action which Israel is entitled to take under the law of naval warfare, and which is less severe than the imposition of a blockade—namely, the exercise of the right to visit and search vessels en route to Gaza in order to determine whether they are carrying contraband. The existence of this alternative, which is action more calibrated to achieve the objective Israel seeks, indicates that Israel’s imposition of a total maritime blockade may be seen as disproportionate within the meaning of Article 102.b of the San Remo Manual.

The relevance of the right to stop and search is reinforced by Articles 103 and 104 of the San Remo Manual, which may be relied upon in order to ameliorate the humanitarian situation in Gaza. Article 103 provides:

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 organisation which offers guarantees of impartiality, such as the International Committee of the Red Cross.

Article 104 provides:

The blockading belligerent shall allow the passage of medical supplies for the civilian population or for the wounded and sick members of armed forces, subject to the right to prescribe technical arrangements, including search, under which such passage is permitted.

While the text of these Articles draws on Article 70 of Additional Protocol I which provides for relief actions, it simplified the language used to make “the unequivocal statement that the blockading power is obliged to allow the transit of relief shipments through the blockade”.[41]

The effect of these Articles is parallel to the provisions applicable to occupied territory set out in Articles 55.1 and 59-61 of 1949 Geneva Convention IV relative to the Protection of Civilian Persons in Time of War. Article 55.1 provides:

To the fullest extent of the means available to it, the Occupying Power has the duty of ensuring the food and medical supplies of the population; it should in particular, bring in the necessary foodstuffs, medical stores and other articles if the resources of the occupied territory are inadequate.

The ICRC commentary to this paragraph states that it is “a happy return to the traditional idea of the law of war, according to which belligerents sought to destroy the power of the enemy State, and not individuals”. Moreover, it places on the occupant:

a definite obligation to maintain at a reasonable level the material conditions under which the population of the occupied territory lives”.[42]

This standard contrasts starkly with the Israeli government’s argument, accepted by the High Court in Jaber al Bassouini Ahmed et al v Prime Minister and Minister of Defense, that it need not allow the transit into Gaza of “goods in amounts beyond that necessary for basic humanitarian needs”.[43] This standard appears to be unknown to the law of armed conflict.

Articles 59-61 of Geneva Convention IV deal with relief actions undertaken by States other than the occupant or by impartial humanitarian organisations, such as the ICRC, if “the whole or part of the population of an occupied territory is inadequately supplied”. The occupant is under an obligation (“shall agree”) to these relief actions “and shall facilitate them by all the means at its disposal”.[44] Dinstein affirms that the obligation on the occupant to allow these relief consignments is “unconditional”.[45] The ICRC Commentary sees Article 59.3 as “the keystone of the whole system”.[46] It provides:

All Contracting Parties shall permit the free passage of these consignments and shall guarantee their protection.

Further, the Commentary expressly and unequivocally states that relief consignments for occupied territories must be allowed to pass through blockades: “they cannot under any circumstances be declared war contraband or be seized as such by those enforcing the blockade”. Moreover, their protection must be guaranteed, as it is “not enough merely to lift the blockade and refrain from attacking or confiscating the goods…all the States concerned must respect the consignments and protect them when they are exposed to danger through military operations”.[47] As under the terms of the San Remo Manual, these relief operations are subject to regulation of their technical arrangements, and may be searched,[48] but their provision does not relieve the occupant of its obligation to ensure reasonable material conditions for the population of the occupied territory under Article 55.[49]

The conclusion to be drawn is clear. Whether under the law applicable to blockades, or the law applicable to occupied territory, Israel is under a duty to facilitate the provision of humanitarian relief to the civilian population of Gaza, subject to the right of inspecting the goods in question if relief is provided by third States or by impartial humanitarian organisations.

V. Interception of vessels attempting to breach the blockade:

a. assuming that the blockade is lawful:

Leaving to one side the question whether Israel’s continued occupation entails that a blockade could not lawfully be imposed on Gaza in the first place, Israel is entitled to prevent breaches of its blockade. It must be emphasised that this is only an entitlement, and not a right, because a vessel attempting to breach a blockade is under no correlative duty to stop when intercepted, and may try to escape and resist capture. It does so at its peril, however, because the intercepting warship may attack a merchant vessel which, after prior warning, clearly resists capture.[50] Any attack, however, is subject to the general rules regarding precautions in attack, and must not be launched if it is expected to cause collateral casualties or damage which would be excessive in relation to the concrete and direct military advantage anticipated from the attack as a whole.[51]

While the interception of a vessel attempting to run a blockade may legitimately take place on the high seas, O’Connell’s views on limited warfare and the containment of hostilities to the territory of the belligerents could circumscribe the maritime areas in which this should take place. Given Israel’s control of the maritime areas off Gaza, and the lack of a credible threat to the safety of Israel’s naval forces from the territory, this could arguably curtail the rayon d’action of the blockading forces, and restrict interception to the immediate area of the blockade line. This is, however, probably more an argument of discretion than law.

b. assuming that the blockade is a nullity:

If Israel’s continued occupation entails that a blockade could not lawfully be imposed on Gaza and thus was a nullity from the outset, any interception of vessels on the high seas by warships is unlawful. As demonstrated above, the interception of foreign-flagged vessels on the high seas cannot be classified as action taken as a measure of law-enforcement: only an armed conflict paradigm is relevant. Accordingly, the interception of the Mavi Marama flotilla and the Rachel Corrie by Israeli naval vessels amounted to unlawful uses of force prohibited by Article 2.4 of the UN Charter. These actions could only be justified by Israel through reliance on the right of self-defence under Article 51 of the UN Charter. In the instant case, Israel has not invoked Article 51, and it is simply not credible to claim that an armed attack on Israel had been committed by the intercepted vessels.

Faced with an unlawful armed interception, the crew and passengers of the intercepted vessels had the right of personal self-defence against the attacking forces, the modalities of which are determined by the domestic law of the flag State, by virtue of its exclusive jurisdiction over the vessels. It also has jurisdiction to prosecute the assailants, and also those resisting the attack if the force they used in self-defence was disproportionate to the perceived threat under the domestic law of the flag State.

VI. Reviving more of the past?

In imposing a blockade, Israel relied on a body of law which has been so little used since the close of World War Two that the experts convened to draft the San Remo Manual discussed at length whether blockades were an archaic form of warfare. A minority of the experts thought that “the traditional rules for formal blockade were in complete desuetude”.[52] To determine issues such as the extent of the need for humanitarian assistance in Gaza, another institution little used since World War Two could be revived, namely that of Protecting Powers.[53]

This institution was adapted from the practice of diplomatic relations, where one State may instruct another to safeguard its interests and those of its nationals in a third State. In response to difficulties experienced in the supervision of prisoners of war during World War One, the 1929 Geneva Prisoners of War Convention attempted to ensure the implementation of its provisions through a system of Protecting Powers. This proved to be effective during World War Two but, although the interests of prisoners of war were thus safeguarded, those of civilians in the hands of enemy belligerents were not. Consequently, Protecting Powers were introduced into 1949 Geneva Convention IV,[54] Article 9 of which provides in part:

The present Convention shall be applied with the co-operation and under the scrutiny of the Protecting Powers whose duty it is to safeguard the interests of the Parties to the conflict. For this purpose, the Protecting Powers may appoint…delegates from amongst their own nationals or the nationals of other neutral Powers. The said delegates shall be subject to the approval of the Power with which they are to carry out their duties.

The Parties to the conflict shall facilitate to the greatest extent possible the task of the representatives or delegates of the Protecting Powers.

The authoritative ICRC Commentary underlines that parties to a conflict are under a duty to appoint Protecting Powers-“This is a command”-but notes that Convention IV does not set out the procedure by which they are appointed. This draws on diplomatic practice: the belligerent which wishes its interests to be protected asks a neutral State if it will act as a Protecting Power. If the latter agrees to this, it then asks the other belligerent to authorise it to carry out its duties. This consent is necessary, and a belligerent is not under a duty to accept any nominated Protecting Power automatically, but it cannot reject every nominee.[55] While an impartial humanitarian organisation, such as the International Committee of the Red Cross, may act as a substitute for a Protecting Power (see Article 11 of Geneva Convention IV), it is not a State and thus does not have at its disposal the array of political and diplomatic tools and rights of audience in international organisations a Protecting Power would possess. Their appointment could achieve the impartial and authoritative supervision of the conduct of the armed conflict between Israel and Hamas.



1.Case of the SS Lotus (France v Turkey), PCIJ Ser.A, No.10, 18-19 and 25.

2.The first preambular paragraph of this Convention sets out the parties’ intention “to codify the rules of international law relating to the high seas”, thus it was intended to restate existing law on the matter.

3.Office for the Coordination of Humanitarian Affairs, Occupied Palestinian Territories, The humanitarian monitor (April 2010),

4. In this paper, “blockade” is used in its narrow legal sense as an instrument of naval warfare. In particular, it does not refer to the restrictions placed on the import of goods into Gaza by land which some, loosely, term a “blockade”. The entry of goods by land into territory subject to a maritime blockade does not affect the efficacy (and consequently the legal validity) of that blockade.

5. NWP 1-14M; MCWP 5-12.1; COMDTPUB P5800.7A, July 2007.

6. For a discussion of the advantages which may accrue to States by shifting the classification of a situation from a law enforcement paradigm to one subject to the law of armed conflict, see Kretzmer D, Rethinking application of IHL in non-international armed conflict, 42 Israel Law Review 1 (2009), 24.

7.Doswald-Beck L (Ed), San Remo Manual on international law applicable to armed conflicts are sea (Cambridge UP: Cambridge: 1995) 176 [hereinafter San Remo Manual].

8.HCJ 9132/07 (27 January 2008): see the opinion of President Beinisch, para.12.

9.For a range of views, see, for example, Aronson G, Issues arising from the implementation of Israel’s disengagement from the Gaza Strip, 34 Journal of Palestine Studies 49 (2005); Benvenisti E, The law on the unilateral termination of occupation, in Giegerich T and Heinz U (eds), A wiser century? Judicial dispute settlement, disarmament and the laws of war 100 years after the Second Hague Peace Conference (Walther Schücking Institute, Kiel: 2009); Bockel A, Le retrait israelien de Gaza et ses consequences sur le droit international, 51 Annuaire francais de droit international 16 (2005); Bruderlein C, Legal aspects of Israel’s disengagement plan under international humanitarian law; Gisha–Legal Center for Freedom of Movement, Disengaged occupiers: the legal status of Gaza (2007); Kaliser MS, A modern day exodus: international human rights law and international humanitarian law implications of Israel’s withdrawal from the Gaza Strip, 17 Indiana International and Comparative Law Review 187 (2007); Mari M, The Israeli disengagement from the Gaza Strip: an end of the occupation?, 8 Yearbook of International Humanitarian Law 356 (2005); Scobbie I, An intimate disengagement: Israel’s withdrawal from Gaza, the law of occupation and of self-determination, 11 Yearbook of Islamic and Middle Eastern Law 3 (2004-2005), reprinted in Kattan V (ed), The Palestine question in international law (British Institute of International and Comparative Law: London: 2008) 637; and Shany Y, Faraway, so close: the legal status of Gaza after Israel’s disengagement, 8 Yearbook of International Humanitarian Law 3