A. Introduction

 

The International Court of Justice (hereinafter the ICJ) delivered the Advisory Opinionon “Legal Consequences arising from the Policies and Practices of Israel in the OccupiedPalestinian Territory, including East Jerusalem” (hereinafter the Advisory Opinion) in 2024. The Advisory Opinion addresses, inter arial, the issue of illegality of Israeli occupation, prompting the question of whether an occupation (as opposed to specific breaches of jus inbello) can be unlawful. Exactly this question is answered in this paper.

 

First, the paper explores the legal framework pertaining to the determination of theillegality of occupation. This is done through a brief summary of the Advisory Opinion,followed by identification and analysis of the legal rules relevant for assessing the illegality ofoccupation. Secondly, the examined legal framework is applied to the case of the Occupied Palestinian Territory (hereinafter the OPT). Finally, the paper ends with a conclusion providinga summary of the findings. As for delimitations, the paper does not address the existence of Israeli occupation in the relevant parts of Palestine and proceeds from the occupied status of Gaza and West Bank as established. The paper’s scope also excludes Israel’s conduct and theevents after 7 October 2023 (with the exception of the UNGA Res ES-10/24) as these developments are also not discussed in the Advisory Opinion.

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B. Legal Framework relevant for the Determination of the Illegality of Occupation

The present chapter analyses the legal norms relevant for the determination of the illegality of occupation. It begins with a brief summary of the Advisory Opinion, then proceeds to an examination of the interaction between the illegality of occupation and jus ad bellum, an analysis into the relevance of the self-determination framework and an appraisal of the right to self-defence as a possible justification excluding the illegality of occupation.

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I. The Approach of the ICJ in the Advisory Opinion summarized

The ICJ determined illegality of Israeli occupation through the prisms of the right to self-determination and jus ad bellum (ICJ, 2024, p. 34). In applying the jus ad bellum framework, the Court defined annexation, then identified Israel’s actions amounting to annexation and, lastly subsumed them under the prohibition of use of force and forcible acquisition of territories (ICJ, 2024, p. 47-53). Then, the ICJ applied the self-determination framework by affirming its importance as a right, confirming its jus cogens status and identifying Israel’s conduct inconsistent with it (ICJ, 2024, p. 65-68). This argumentation on Israel’s acts violating the jus ad bellum norms and the right to self-determination is like a bridge to come to a finding of the illegality of Israeli occupation. In particular, the Court, before pronouncing on illegality, stated that Israel’s breaches of the aforesaid norms had an impact on lawfulness of Israeli occupation.4 What is this impact? It lies in making the occupation illegal, since, to rephrase the relevant paragraph, annexing of the OTP and depriving Palestinians of the right to self-determination is an abuse of occupation, rendering it illegal.5 In other words, the unlawfulness of Israeli occupation derives from violating the aforesaid right and the prohibition of use of force and forcible acquisition of territories.

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II. The Illegality of Occupation and Jus ad bellum

Now that the position of the ICJ in its Advisory Opinion has been presented, this sub-chapter of the present paper turns to exploring the illegality of occupation under jus ad bellum and alternative views expressed.

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1. Applicability of the Use of Force Rules to the Illegality of Occupation

The majority position of the ICJ summarized above was not entirely shared by some judges. Judges Abraham, Aurescu and Tomka disagreed with the majority argumentation that the Israeli occupation itself was illegal on account of annexation under jus ad bellum.6 Rather, they viewed annexation by an occupying power as a conduct to be assessed as a breach under jus in bello.7 That is to say, these judges differentiated between annexation and the illegality of occupation as categories of jus in bello and jus ad bellum, respectively. Thus, they did not dispute that an occupation as such can be illegal under the latter legal framework.8 Nevertheless, they asserted that the ICJ should not have found the jus ad bellum illegality of the Israeli occupation. Firstly, the lack of evidence meant for these judges that it was impossible to establish the ab initio illegality of the use of force that led to the Israeli occupation in 1967.9 However, the ab initio lawfulness is of lesser importance, because, as pointed out by judges Nolte and Cleveland, “the relevant question before the Court today is whether Israel’ continuing presence in the Occupied Palestinian Territory can still be justified under the jus ad bellum”10. The question asked in the United Nation’s General Assembly (hereinafter UNGA) resolution seeking the ICJ’s position should be understood in this way, because, as Judges Tomka, Abraham and Aurescu themselves recognized, “it is not impossible that, even if an occupation is initially lawful, it ceases to be so at a certain point in time”11. Even so, these judges claimed that the illegality of occupation cannot ensue from the flow of time.12 This argument cannot undermine the majority’s reasoning, because the latter grounds the illegality not on a (prolonged) duration of occupation but on, inter alia, the proscription of annexation under the jus ad bellum framework.13 The exclusion by Judges Tomka, Abraham and Aurescu of this framework concerning annexation from determining the illegality of occupation is incorrect as shown below. 

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To demonstrate the relevance of the jus ad bellum norms, one should first define the legal concept of occupation. The starting point is the customary14 meaning of occupation under Article 42 of the Regulations of (Hague) Convention (IV) respecting the Laws and Customs of War on Land: “Territory is considered occupied when it is actually placed under the authority of the hostile army. The occupation extends only to the territory where such authority has been established and can be exercised”. The criterion of effective control over an occupied territory has been derived from this definition.15 The effective control does not mean that occupying power receives the sovereignty over the occupied territory.16 Indeed, occupation does not remove sovereignty from an occupied state to place it in the occupier’s hands.17 Hence, another important principle of the occupation law is the temporariness of occupation.18 However, since these principles are both tenets of the occupation law as part of jus in bello, one may ask how do the jus ad bellum rules enter into the picture? The answer lies in the connection between the aforementioned principles, on the one hand and, on the other hand, the prohibition of use of force and the ensuing prohibition of annexation as the acquisition of territory through use of force. Indeed, the non-transfer of title and the temporariness characterizing occupation derive from and mirror those jus ad bellum prohibitions.19 This is confirmed by the history of development of the notion of occupation under international law. In particular, the 1874 Brussels Conference resulted in drafting the Brussels Declaration.20 Although not ratified by the participating states, the Brussels Declaration acknowledged that the occupying power substitutes the legitimate sovereign, i.e. the occupied state, in exercising the official authority to preserve order, without, however, taking away sovereignty from the occupied state.21 This development was followed by the 1907 Hague Conference that adopted the (Hague) Convention (IV) respecting the Laws and Customs of War on Land and its Regulations. The fact that Article 43 of the Regulations obliges the occupier, in the process of maintaining public security and order, to respect the laws in force, i.e. the already existing conditions, in the occupied territories indicates that the occupier is only a temporary and non-sovereign administrator of those territories.22 Thus, these historical developments demonstrate the birth of the difference between occupation and the previously established norm of conquest which allowed the obtainment of title over the occupied defeated countries.23 The conquest was finally outlawed with the adoption of the principle of self-determination of peoples and the prohibition of use of force in the UN Charter in 1945.

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Thus, the foregoing reasoning demonstrates a strong link between this jus ad bellum framework and the temporariness and non-sovereignty principles of the law of occupation as the latter protect the former. Moreover, despite a claim of one author,25 this link does not undermine the tenet of separation of jus in bello and jus ad bellum. According to it, the laws of war must be respected by all parties of armed conflict, regardless of which of them used force according to jus ad bellum and which one did not.26 This separation stays intact because the determination of the illegality of occupation based on the annexation prohibition is content-wise a different exercise. It means not a release of the parties from their jus in bello duties, but the establishment of whether occupation has turned from a regime of temporariness and non-sovereignty into an annexationist regime usurping the sovereign title. This view that the jus ad bellum illegality of occupation does not remove commitments under international humanitarian law (hereinafter IHL) is also supported by the wording of Article 47 of the Fourth Geneva Convention Relative to the Protection of Civilian Persons in Time of War of 12 August 1949, stipulating that no annexation shall take away from the protected persons in the occupied territories “the benefits of the present Convention”. The position that the jus ad bellum illegality framework does not mean or lead to the abolition of the aforementioned separation principle is also confirmed by the Articles of Responsibility of States for Internationally Wrongful Acts (hereinafter ARSIWA). As an occupation unlawful under jus ad bellum is an internationall wrongful act, then, per Article 30(a) of the ARSIWA, the consequence of this illegality is cessation of the act,27 and not a discharge of the parties from their jus in bello obligations.

Moreover, the aforesaid separation principle does not require to consider the law of occupation or IHL in isolation from the rest of the international law. The law of occupation is not a closed system detached from other norms. Instead, the law of occupation “like all international law, is affected by the process of fragmentation, in which multiple normative frameworks and institutions govern any given instance”28. Therefore, occupation is not only a question of fact under IHL but can be subject to legality assessment under jus ad bellum.

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Finally, at the end of this part of the present sub-chapter, a more detailed attention should be paid to the argument, which appeals to the absence of a restriction on the duration of occupation under international law to refute the concept of unlawfulness of occupation.29 However, the absence of such a limitation does not mean that an occupying power is allowed to transform occupation into annexation in breach of the prohibition on acquisition of territory by force under jus ad bellum. The non-existence of a deadline cannot rebut or deny the possibility of occupation becoming unlawful because it can be conceived that an occupying power prolongs occupation without a determined temporal end-point in a manner that assimilates occupation into annexation. An opposite scenario of prolonging occupation without transforming it into annexation is also possible. Therefore, the duration or absence of a temporal limit is in itself insufficient to find legality or illegality. Instead, one should focus on the concept of annexation which is explored in the following part of the present sub-chapter.

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2. Annexation and its Relation to Occupation

Annexation means “the forcible acquisition of territory by one State at the expense of another State”.30 It consists of “the effective occupation of the territory in question and the clear intention to appropriate it permanently”.31 Annexation is outlawed under the prohibition of use of force and the ensuing prohibition of forcible territorial acquisition under Article 2(4) of the UN Charter and customary international law.32

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​The annexation definition provided above depicts the relationship between annexation and occupation. First of all, it follows that any annexation includes in itself occupation while not every occupation amounts to annexation. This is so because of a vital distinguishing factor. As already mentioned, the legal concept of occupation denotes a temporary state and, thus, does not include the intent or acts to permanently acquire the occupied territories. In contrast, an annexation, by definition, means control exerted by one state to make a territory of another country its own perpetually. Such a territorial incorporation can take place in two forms: de jure annexation and de facto annexation. In the former case, annexation is directly expressed and carried out through a formal explicit declaration or act by a state.33 In the latter situation, it is implicit and reflected in the state conduct.34 Occupation may take either forms of annexation in practice, but, as the factual one is not explicit and harder to establish, indicators have been proposed to identify the transformation of occupation into a de facto annexation. In particular the UN Special Rapporteur has suggested the following test of lawfulness of occupation: the occupier must not annex territories under its occupation, the latter must be temporary, conducted in the most beneficial way for the interests of the occupied population and administered in good faith.35 This test can be considered suitable in overall, but it does have some minor flaws. The criterion of good faith may be somewhat superfluous because it measures compliance with the rest of the conditions and, thus, overlaps with them.36 The addition of compliance with IHL and human rights obligations under the good faith criterion also seems unnecessary as it is already included in the best interest element requiring conformity with human rights and IHL.37 Moreover, the separation of temporariness and non- annexation seems somewhat artificial because the prohibition of annexation incorporates and implies the temporary nature of occupation that must end with returning the occupied territories to their rightful sovereign. In addition to the Special Rapporteur’s approach, another test has been suggested to assess the lawfulness of occupation by applying the indicators of permanence and actions constituting annexation.38 This test more closely resembles the aforementioned general definition of annexation and, specifically, the characterization of its de facto form by the ICJ as “a “fait accompli” on the ground that could well become permanent”.

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All of the described tests support the possibility of occupation becoming unlawful on account of turning into annexation, i.e. the ICJ’s approach in the Advisory Opinion. It is also supported in literature.40 Nevertheless, there is a contrary position of one author relying on the difference in references to occupation and annexation in the UNGA Resolution 3314.41 This document classifies as an act of aggression “any military occupation, however temporary, resulting from such an invasion or attack, or any annexation by the use of force of the territory of another State or part thereof”.42 The aforementioned author points out that this aggression definition includes every forcible annexation of occupied territories whereas inclusion of occupation “appears to be restricted, however, to occupation born through an unlawful use of force (“resulting from… invasion or attack”)”.43 Therefore, the author concludes that depicting occupation as an act of aggression “depends only on the circumstances underlying the formation of the occupation”.44 This position is incorrect because it fails to realize that annexation is, by definition, in itself occupation and, therefore, there exists a type of occupation – the one amounting to annexation – that can be and is illegal (under the prohibition of forcible acquisition of territory). Nonetheless, the same author, in a different article, appeals to state practice to reject the concept that an initially lawful occupation resulting from self-defence can become tainted with illegality.45 In particular, the author dismisses the weight of the UNGA resolutions mentioning the illegality of Israeli occupation by pointing out the absence of support of western democratic countries for these resolutions.46 However, the situation has changed with the UNGA Resolution ES-10/24 which agrees with the ICJ’s reasoning in the Advisory Opinion. It expressly recognizes that the Israeli presence in the occupied territories has become unlawful due to “the sustained abuse by Israel of its position as an occupying Power, through annexation and an assertion of permanent control over the Occupied Palestinian Territory and continued frustration of the right of the Palestinian people to self-determination”.47 Importantly 124 states voted in favor of the Resolution in a remarkable contrast to 43 abstentions and 14 votes against.48 Moreover, the states voting in favor did include western democracies, such as Finland, Belgium, Estonia, France, Ireland, Greece, Iceland, Latvia, Spain, Luxembourg, etc.49 Moreover, the difference in numbers of the western democracies supporting and those abstaining was not considerable.50 Only 3 western democracies (the USA, Hungary, Czech Republic) voted against.51 Thus, the aforesaid argument about the non-existence of western support is no longer telling. In this regard, the positions expressed by states in the advisory proceedings before the ICJ are also relevant. Apart from Palestine, 29 out of 49 of these states (including western countries) expressly or impliedly considered the Israeli occupation as illegal due to annexation – the forcible acquisition of territory.52 The same view was held by 3 international organizations (the League of Arab States, the Organization of Islamic Cooperation and the African Union).53 Out of the 20 remaining states, 14 countries did not address the question of illegality based on annexation, while 5 countries addressing this matter did not provide a clear yes/no answer and the USA implicitly rejected the illegality.54 In light of the recent state practice described here, it is more convincing to hold that occupation becomes unlawful when it turns into annexation.

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3. The Jus Cogens Nature of the Annexation Prohibition

After making a case for the illegality of occupation on account of annexation, the next issue to be examined is that of justifiability. In other words, is there a legal justification excluding or eliminating the unlawfulness of occupation that has assimilated into annexation? The question turns on the foundational rules of the modern public international law – the prohibitions of use of force and forcible acquisition of territory. As already mentioned, these norms proscribe annexation. However, do they do so in absolute terms? The answer is yes, because the prohibition of use of force is a peremptory norm of international law. This jus cogens nature is recognized by States,55 the International Law Commission (ILC),56 the UNGA57, the ICJ58 and literature.59 As a corollary to prohibition of use of force, the prohibition of territorial acquisition by use of force is also a peremptory rule.60 These non-derogable norms encompass within their proscriptive scope only an unlawful resort to force. Thus, the force applied in self-defense is not precluded because the right to self defence is one of the legally accepted exceptions under the aforesaid prohibitions both in the UN Charter and customary law.61 In other words, the use of force and forcible acquisition of territories is categorically not allowed whereas the defensive force – is. Therefore, the scope and interpretation of the right to self-defense are of crucial importance for determining whether the occupation pursuing annexation as well as security of the occupier can be justified or not. This issue is examined in the 4th sub-chapter of this chapter, but, before that, attention should be paid to another matter closely connected to the aforementioned prohibitions and also relevant in the context of the potential self-defence justification. That matter is the right to self-determination.

III. The Right to Self-determination and the Illegality of Occupation

In addition to annexation of the Palestinian territories, the Advisory Opinion also relied on the violation of Palestinians’ right to self-determination to arrive at the illegality of the Israeli occupation.62 Therefore, the present sub-chapter analyses how this unlawfulness can be derived from the aforementioned right.

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1. The Definition of the Right to Self-determination

The drafters of the UN Charter included the notion of self-determination of peoples as a principle in Article 1(2) of the Charter. In the following decades, this notion became legally binding as a principle as well as a right under international law, through practice of the UN organs and states. In the common Article 1 of the ICCPR and the ICESCR, for example, the self-determination was codified as a right by the member states. Moreover, the ICJ referred to it as an erga omnes right and “one of the essential principles of contemporary international law”.63 In light of such a characterization and an almost universal ratification of the ICCPR and the ICESCR, the right to self-determination can be considered as a customary rule. This is also demonstrated by the inclusion of the right in the UNGA Resolution 2625 on “The Declaration on Principles of International Law concerning Friendly Relations and Co-operation among States”, which mirrors customary international law.64 This Resolution reads that “By virtue of the principle of equal rights and self-determination of peoples enshrined in the Charter of the United Nations, all peoples have the right freely to determine, without external interference, their political status and to pursue their economic, social and cultural development”65. This definition of the right to self-determination is also contained, with an almost identical wording, in the aforesaid common Article 1, which, in paragraph 2, highlights the free disposal and control of natural resources and wealth by people. This aspect clarifies the meaning of economic development as part of the overall right to self-determination. As for deciding on the political status, this element has an internal dimension, whereby a people decides on its own internal governmental organization, and also an external part meaning “the establishment of a sovereign and independent State, the free association or integration with an independent State or the emergence into any other political status freely determined by a people”.66 The aforesaid UNGA Resolution grants the right to self-determination to all peoples and obliges states to respect it in conformity with the UN Charter.67 In this connection, the question arises whether states can violate this obligation through occupation. This issue is discussed in the next part of this sub-chapter.

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2. The Relation between the Right to Self-determination and Occupation

It might be considered that occupation automatically undermines or is at odds with the right to self-determination.68 The logic behind this view is understandable because an occupying power exercises those official functions that would normally be carried out by a sovereign granted legitimacy by people. In any case, the foreign state, as a non-sovereign, does not receive this authority from the occupied population, but from the relevant rules of IHL. Therefore, occupation interferes with the right of self-determination of the occupied people whose freedom of decision-making is significantly limited. However, can one find, on this basis, that any occupation is per se a breach of the right to self-determination? The answer should be in the negative for several reasons. Firstly, the legal regime of occupation emerged and developed as the opposite to the right of conquest, as already explained above. This distinction, the mandatory temporariness and the non-transfer of title underpinning the occupation framework indicate that this legal system is intended to resist or prevent annexation.69 While occupation interferes in the exercise of the right to self-determination, it simultaneously protects this right from the greater peril of annexation. Therefore, occupation is a temporary suspension of the normal exercise of this right and not in itself a violation thereof. This argument is also supported by a close reading of the UNGA Resolution 2625 (XXV). The latter prohibits states from undertaking a forcible action depriving the people of the right to self-determination.70 The verb “deprive” should be highlighted because it qualifies which type of forcible activity is proscribed. The dictionary meaning of this verb is to take away or withhold something from someone or something.71 Thus, the deprivation of the right to self-determination means a situation in which this right is taken away from people. In light of this interpretation, occupation violates the right to self-determination when it permanently takes away, denies and makes impossible its exercise. Such an interpretation is also reflected in literature.72 It can also be seen in the opinions of some of the ICJ judges. Judges Nolte and Cleveland, for example, refer to Israel seeking “to permanently obstruct the exercise of the right of the Palestinian people to self-determination”73, while Judge Tladi mentions “the denial of the right of self-determination”.

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Considering the aforesaid reasoning, the issue emerges as to when an occupying power deprives people of their right to self-determination. An example of such a situation is when the occupation transforms into annexation meant to last perpetually.75 In such a case, the occupying power exerts control over the life in the occupied territory, by which control it is usurping sovereignty and placing itself in the position of the ultimate decision-maker instead of the occupied population, thereby depriving it of the right to self-determination.

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Apart from annexation, the occupied people are deprived of their right to self-determination when the occupying power systematically and gravely violates their human rights, without acquiring their territory. In such a case, the deprivation of the right of self-determination results from the close link between it and other fundamental guarantees. Indeed, according to the Committee on the Elimination of Racial Discrimination, the realization of self-determination requires all states to promote global compliance with human rights per the UN Charter.76 Moreover, the 1993 Vienna Declaration and Programme of Action stipulates that “All human rights are universal, indivisible and interdependent and interrelated”77. In light of this strong interconnection, it is not possible or extremely difficult for people to exercise the right to self-determination when their other fundamental rights are systematically, seriously violated (e.g., they are subjected to violence, killings, torture, arbitrary arrests or detentions, forced to live in inadequate conditions or to leave their homes, they cannot express their positions freely, etc.). Thus, occupation deprives the occupied population of its right to self-determination when it persistently and seriously breaches its other fundamental guarantees. Such an occupation is illegal even when it does not amount to annexation. In particular, Article 2(4) of the UN Charter prohibits the use of force “in any other manner inconsistent with the Purposes of the United Nations”. The occupation, which deprives the occupied people of the right to self-determination through serious human rights violations, is inconsistent with the UN’s purposes enshrined in Articles 1(1) and 1(2) of the UN Charter. Thereby, such an occupation violates Article 2(4) of the UN Charter and is illegal.

In light of the foregoing analysis, occupation violates the right to self-determination when it turns into annexation and/or deprives the occupied population its right to self- determination by systematically and gravely violating their human rights. This conclusion, in turn, leads to the issue of whether the illegality of a breach of the right to self-determination can be ruled out in certain circumstances or not. To answer this question, derogeability from this right should be examined.

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3. The Jus Cogens Nature of the Right to Self-determination

The possibility to derogate from the right to self-determination depends on whether it constitutes a jus cogens norm or not. In this regard, it is useful to refer to the Annex to the UNGA Resolution 2625 (XXV) to see how a derogation can be manifested. According to the Annex, the right to self-determination is violated by “alien subjugation, domination and exploitation”.78 This phrase has been interpreted as covering domination by one state of “the people of a foreign territory by recourse to force”.79 This might be construed to include any occupation, but this view would be incorrect. In light of the reasoning in the previous part of this sub-chapter, the more convincing interpretation should encompass only an illegal occupation which is the case, e.g., during annexation. Therefore, a derogation from the right to self-determination may in practice be manifested through such an illegal occupation which is subject to the absolute prohibition of the use of force and the forcible territorial acquisitions. To allow derogating from the right to self- determination in this way would breach the just mentioned prohibitions and erode their jus cogens character. The right itself would also be undermined, considering that it is protected against annexation through the proscriptions of the use of force and the forcible territorial acquisitions. This argumentation mirrors the ICJ’s statement in the Advisory Opinion. Namely, the ICJ stated that the right to self-determination is a jus cogens rule “in cases of foreign occupation such as the present case”.80 This cited wording can be understood with the help of the preceding passages of the Advisory Opinion where the ICJ had already established the annexation of the OPT by Israel.81 Therefore, “cases of foreign occupation such as the present case”82 should be understood as an occupation amounting to annexation in which instance, at least, the right to self-determination is a peremptory norm. The ICJ’s position was endorsed in the UNGA Resolution adopted by a significant majority of 124 member countries that voted in favor.83 Such a support can be indicative of the states’ approval of the jus cogens nature of the right to self-determination. In addition, the peremptory character is recognized by the ILC, the Human Rights Council and in literature.84 However, at least one author advances the argument of the right to self-defence to deny the illegality of occupation which has turned into annexation and thereby breaches the right to self-determination and the prohibitions of the use of force and the forcible territorial acquisition.85 This argument is explored in the following chapter.

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IV. The Right to Self-defense as alleged Cure for the Illegality of Occupation

To eliminate the illegality of occupation having turned into annexation, it is argued tha the occupying power can still rely on the right to self-defence when the occupation serves “both legitimate interests (security) and illegitimate interests (annexation) of the right to self-defense”.86 This reasoning alleges that the occupier can still rely on the right to self-defense even when it seeks to achieve an illegitimate goal as well.87 This argument is wrong for the 3 reasons explained below.

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1. The Necessity and Proportionality of Self-defence

A state’s right to exercise (force in) self-defence is provided in customary international law and Article 51 of the UN Charter and must satisfy the requirements of necessity and proportionality.88

The necessity condition examines whether it was necessary to use force to achieve the aim pursued by self-defence, i.e., whether this aim could have been achieved by alternative means.89 Thus, this requirement is closely connected to the purpose of self-defence which is repelling an armed attack and, thereby, re-establishing the status quo.90 Therefore, pursuing other objectives, including annexation and denial of a people’s right to self-determination, fails to meet the necessity criterion.91

As for the proportionality requirement, it means that the degree of the defensive response must be proportional to stop and neutralize the armed attack.92 Thus, this condition, similarly to necessity, restricts the right to self-defense to returning to the situation that existed before the armed attack,93 i.e. the purposes of annexation and denial of a people’s right to self-determination are not covered.

In light of the requirements of necessity and proportionality, an occupying power can only invoke the right to self-defence when it has the sole objective of restoring the status quo ante. In contrast, when an occupation has transformed into annexation, the reliance on self-defence is not limited to the aforementioned exclusive goal, but is also aimed at the forcible acquisition of the occupied territories and the deprivation of the right to self-determination of the occupied population. In such a case, the necessity and proportionality criteria are not fulfilled and, consequently, the occupier cannot refer to the right to self-defence to deny the illegality of occupation. Nevertheless, there is a different approach, according to which the proportionality and necessity conditions are met provided that the main purpose of the resort to self-defence is defensive, i.e., returning to the preexisting situation, and additional illegitimate aims are only secondary.94 Such a position is incorrect because it opens the door to abusing the right to self-defense, as explained in the following paragraphs.

2. The Danger of the Abuse of the Right to Self-Defence

Abuse of rights denotes “exercising a right for an end different from that for which the right was created, either in a way which impedes the enjoyment by other States of their own rights or to the injury of another State”95. The prohibition of the abuse of rights is binding as it is a manifestation of the general international law principle of good faith expressed in Article 26 of the Vienna Convention of the Law of Treaties (VCLT).96 The good faith principle is also contained in Article 2(2) of the UN Charter stipulating that all UN members “shall fulfill in good faith the obligations assumed by them in accordance with the present Charter”. This principle requires states to not defeat the purpose of a treaty through its application.97 Hence, the abuse of rights as a bad faith application of rights provided under a treaty can hinder the achievement of the treaty’s aim.

Per Article 2(2) of the UN Charter cited above, member states must comply, in good faith, with their obligation, under Article 2(4), to not use force unlawfully. In other words, states may only use force lawfully in a manner that does not contradict the Charter’s purposes, the main purpose arguably being the maintenance of international peace and security (Article 1(1) of the UN Charter). This aim would not be achieved, but would be endangered and Article 2(2) of the Charter violated if an occupier were allowed to rely on the right to self-defence to rebut the illegality of occupation, when the defensive purpose of the occupation was not exclusive and sole but primary to the secondary aims of annexation and denial of the right to self-determination. In such circumstances, the invocation of the right of self-defence would enable the abuse of this right, in contrast to the case when repelling an armed attack is the only objective allowed under this right. In the latter case, the establishment of illegality consists of only 1 step: the assessment of whether only the defensive purpose is pursued or not. If a different aim is sought exclusively or additionally, then illegality is found. In contrast, were it permitted to advance secondary purposes, such as acquisition of territories, in addition to the main defensive one, then the establishment of illegality would comprise 2 steps: firstly, the assessment of whether both the defensive and other illegitimate goals are pursued or not and, if the answer is affirmative, then, secondly, the analysis of which one of them is primary and which – secondary. It is this second step which would give states the leeway to (falsely) claim that their primary purpose is defensive instead of an illegitimate, e.g. annexationist, one. In the context of occupation, the occupier would invoke the right to self-defense in bad faith in order to circumvent the right to self-determination and the prohibition on the acquisition of territory through force and to reject the illegality of occupation. This would, in turn, very likely endanger the maintenance of peace and security – the UN aim under Article 1(1) of the UN Charter. Thus, the good faith principle precludes the invocation of the right to self-defence for aims other than its legitimate defensive purpose. It thereby excludes the reliance on self-defence to remove the illegality of occupation annexing the occupied territories and denying the occupied people their right to self-determination. The argument that the right to self-defence cannot be used in such circumstances is also confirmed by the rules of treaty interpretation which are elaborated in the next paragraphs.

3. Interpretation of Article 51 of the UN Charter

Article 31 of the VCLT reflects customary rules of treaty interpretation.98 The first paragraph of Article 31 stipulates that “A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose”. Thus, this provision mentions textual, teleological and systemic methods of treaty interpretation. The interpretation process usually starts from the textual approach, looking at the common meaning of the language of the treaty clause in question.99 However, this does not mean that this method necessarily prevails over the others. According to the ICJ, the textual interpretation should not be used if its outcome contradicts the context or the aim of the treaty or its relevant provision.100 As for the teleological method, it involves the determination of a treaty’s object and purpose in light of which the treaty and its clauses should be construed, i.e. the interpretation should seek to further these aims.101 The contextual approach consists of a systemic exercise, i.e., looking at the treaty as a one whole system, not focusing only on the specific provision, sentence or word to be interpreted and considering the meaning and role of other parts of the instrument and where they are located.102 Finally, Article 31 of the VCLT includes the requirement of elucidating the meaning of a treaty and its clauses in good faith, which must be taken into account during the whole interpretation process and which excludes clearly irrational outcomes resulting from other interpretation means.103

The aforementioned methods should guide the interpretation of Article 51 of the UN Charter providing the right to self-defense. In this connection, some authors seems to have applied the textual approach to argue that the right to self-defence can rule out the illegality of occupation.104 In particular, they advance the argument that the right to self-defence overrides other provisions of the UN Charter (including the self-determination of peoples) on the basis of the following wording of Article 51: “Nothing in the present Charter shall impair the inherent right of individual or collective self-defence”.105 However, the reliance on this literal formulation is wrong because it contradicts the purposes and the context of the UN Charter. Namely, it goes against the preamble and Articles 1(1), 1(2) and 2(4) of the Charter, i.e. the fundamental provisions stipulating the basic principles and purposes of the UN. The principle of the prohibition of the use of force and the purposes of maintaining international peace and security and friendly relations among states based on the principle of self-determination would be undermined if Article 51 were interpreted as superseding them and thereby enabling an occupation that annexes the occupied territories and nullifies the occupied people’s right to self- determination. Articles 1(1), 1(2) and 2(4) of the UN Charter set the overarching framework for the functioning of the UN and, as such, should guide the interpretation of other clauses of the Charter, including Article 51, instead of being overridden by them.106 This is even more so in respect of the UN Charter since the UN Charter is a founding treaty in which case the teleological interpretation is important to ensure the effective functioning of the organization established by the treaty in question.107

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V. Conclusion on the applicable Legal Framework

In light of the foregoing reasoning in the Chapter B, an occupation is illegal when it transforms into annexation and, thus, contravenes the jus ad bellum prohibitions of the use of force and the acquisition of territory through use of force. It is also unlawful when it violates the right to self-determination. The right to self-defence cannot be invoked to remove this illegality.

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C. The Determination of the Illegality of Israeli Occupation of Palestine’s Territory

Now that the legal framework governing the illegality of occupation has been articulated, it should be applied to the case of Israel and Palestine. This is done in 2 steps. Firstly, it is examined whether the Israeli occupation breaches the prohibition of the use of force and the acquisition of territory through the use of force. Secondly, it is analyzed whether Israel violates the Palestinians’ right to self-determination.

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I. Israeli Occupation as Annexation of the OPT

To qualify the occupation of parts of the Palestine Territory as a de jure annexation, an Israeli formal act or declaration integrating the occupied territories into Israel must be shown. As for de facto annexation, it must be demonstrated that, in the course of exercising effective control, Israel has undertaken actions enabling to create a permanent reality of incorporating parts of the OTP and that this permanency is its intention which may be discerned from its conduct, statements or omissions.

To begin with, Israel applied its legislation, administration and jurisdiction to East Jerusalem and brought it under its municipality of (West) Jerusalem in 1967.108 Then, in 1980, Israel passed the Basic Law which named the whole Jerusalem as its capital.109 Notably, the amendment introduced into the Basic Law in 2000 referred to Israel’s sole control over Jerusalem.110 Thus, Israel de jure annexed East Jerusalem through its formal legislation which directly shows its intention to keep the whole Holy City as its own. In response, these measures were condemned and considered void by the UN.111

In addition to the de jure annexation, Israel has also carried out de facto annexation of East Jerusalem through acts which signal Israel’s intention to permanently keep East Jerusalem as its own territory. The Advisory Opinion correctly mentions some actions, including: the confiscation of land/property for settlements in East Jerusalem, the incorporation of infrastructure of East Jerusalem into that of the western part, the measures disconnecting East Jerusalem from the West Bank, the building permit scheme and (the risk of) demolitions of Palestinian housings in East Jerusalem.112 Another relevant action, e.g., consists of the policies aimed at achieving a demographic majority of Jews in East Jerusalem.113 Finally, Israel’s intention to have lasting sovereignty over East Jerusalem is clear in the statements made by its Prime-Ministers at different times.114

In addition to East Jerusalem, Israel has carried out de facto annexation of large parts of the rest of West Bank. In this connection, the Advisory Opinion mentions the construction and growth of settlements and the related infrastructure in the West Bank in a manner connecting them to Israel, the resulting displacement of local Palestinians and the utilization of natural resources by Israel.115 Such acts do constitute de facto annexation because they are not designed to be “easily reversible”.116 The relevant actions amounting to de facto annexation should be described in more detail to make the de facto annexation more evident.

Israel began the construction of settlements in West Bank soon after the occupation of Palestinian Territory in 1967.117 The building of settlements was mainly carried out through acquiring lands reclassified and regarded as state lands under interpretation and application of Israel’s law.118 In addition, educational and medical institutions, facilities for water, electricity and sanitation have been developed and railways, roads and other infrastructure have been built.119 With expansion of settlements, about 700 000 Israeli Jewish settlers live in 300 settlements and outposts in West Bank (including East Jerusalem).120 Although outposts are not even legal under domestic law, Israel encourages their establishment (e.g., by delivery of basic services) and has also devised legal means to retroactively authorize them.121 In contrast to the settlement expansion, it is almost impossible for Palestinians to construct houses or buildings in West Bank. In particular, since the Military Order #418 handed over to the Israeli Military Commander the zoning and planning power from Palestinian councils, Palestinians have been constantly denied building permits.122 The rejection rate amounted to 90-95% by July 2023, whereas Israel moved forward with the record rate of settlement housing units in January-June 2023.123 The steadily growth of the settlements and outposts indicates Israel’s resolve to perpetually control and seize the territories of West Bank as its own. This annexationist motivation is also confirmed by the extension of Israel’s jurisdiction to settlements and settlers.124 To name an example, the jurisdiction of Israel’s Court of Domestic Affairs was broadened already in 1983 to include and apply several legal fields (labor law, health law, personal status law, etc.) to settlements/settlers.125 The direct application of Israeli laws to settlements proves that Israel actually views itself as sovereign having legitimate legislative authority in West Bank. Moreover, in terms of legislation, the March 2023 amendment to the so called “Disengagement Law” should also be noted because the amendment removed the prohibition of returning to the 4 previously evacuated settlement areas in the North of West Bank.126 This change indicates that Israel plans to expand its presence in and control over West Bank.

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In addition to the settlements and outposts, Israel has also taken over Palestinian lands by designating 48 nature reserves in West Bank and declaring about 30% of Area C in West Bank as military firing zones most of which are not used for military purposes and where Palestinians are not allowed to build constructions.127

Finally, Israel’s annexationist intent is directly expressed in statements of its high-ranking officials.128

As shown by the foregoing reasoning, Israel, as the occupying power, has annexed East Jerusalem and large parts of the rest of West Bank. By doing so, it violated the prohibition of forcible acquisition of territory under jus ad bellum. Therefore, Israeli occupation is illegal.

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II. Israeli Occupation in breach of the Palestinians’ Right to Self-determination

Israeli annexation of East Jerusalem and the rest of West Bank gives rise to a breach of Palestinians’ right to self-determination as Israel effectively took away from them their sovereign decision-making on how to pursue their lives as a people. For clarity, the present sub-chapter, nevertheless, elaborates how Israel, as the occupying power, contravenes Palestinians’ right to self-determination which is recognized by the international community.129

1. Israeli Occupation as Annexation against the Right to Self-determination

The Advisory Opinion correctly identifies how Israel’s annexationist actions violate Palestinians’ right to self-determination.130 The settlements and related road infrastructure, planning and zoning policies, limits on access to Palestinian lands through land capture has fragmented West Bank and damaged Palestine’s territorial unity as an aspect of Palestinians’ right to self-determination.131 This geographic fragmentation along with the forced displacement of Palestinians, the arrival of Israeli settlers in the OPT and the isolation of Gaza affects the demographic integrity of Palestinians as a people by separating them from each other.132 Moreover, Palestinians are unable to freely use their natural resources in the OPT because Israel itself exploits these resources for its own benefit in contravention of Palestinians’ permanent sovereignty over natural resources.133 Thus, Israeli occupation having turned into annexation deprives Palestinians of the right to self-determination and is illegal as a result. Apart from annexation, Palestinians have been deprived of the right to self-determination through human rights violations discussed in the following paragraphs.

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2. Human Rights Violations by Israel against the Right to Self-determination

Persistent and serious breaches by Israel of Palestinians’ human rights in the OPT have been well documented for decades.134 They have included such severe violations as inhumane, degrading treatment or torture, large-scale arrests and imprisonment of Palestinians.135 Notably, arbitrary arrests and imprisonments of Palestinian politicians, human rights defenders and civil society members have targeted and hindered the political self-determination of Palestinians.136 The latter have also been impeded from embracing their cultural identity by such measures as closing or transforming Palestinian religious or cultural spaces.137

Although Israel violates human rights in the whole OPT, this part of the present sub-chapter focuses on the dire situation in Gaza caused by the land, sea and air blockade maintained by Israel since 2007.138 The blockade detaches Gaza from the rest of the OTP and constitutes a major obstacle to Palestinians’ freedom of movement. To enter or leave Gaza, Palestinians must be given a permit by the Israeli Civil Administration in a process described as “military, bureaucratic and arbitrary”.139 Travel to West Bank is allowed only for “urgent and life- threatening medical conditions, essential business and exceptional humanitarian reasons”.140

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Freedom of movement is also restricted through access-restricted maritime zones in Gaza’s coast and access-restricted buffer zones within Gaza along the fence separating it from Israel.141 In turn, such limitations of freedom of movement impact other human rights. The buffer zones, e.g., cover agricultural lands and severely impede agricultural activities and livelihoods of Palestinians.142 Moreover, there has been an acute water scarcity and electricity crisis resulting from Israel’s measures.143 This also undermines the availability and quality of health-care which needs water, sanitation and electricity to function properly.144 Moreover, medical supplies are in shortage because of Israel’s policy restricting the trade in dual use goods.145 Apart from socio- economic rights violations, Israel has breached civil and political rights of Gazans, often to silence protest, such as demonstrations carried out between 30 March and 31 December in 2018, during which Israel used excessive lethal force, killing 189 victims.146 Thus, Israel has persistently and severely violated Palestinians’ fundamental rights for decades.

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3. Conclusion on Israeli Occupation and Palestinian’s Right to Self- Determination

Israeli occupation of the OPT is illegal because it deprives Palestinians of their right to self-determination through annexation of parts of the OTP and continuous breaches of Palestinians’ human rights.

III. The Illegality of Israeli Occupation and the Right to Self-Defence

Unlawfulness of Israeli occupation cannot be excluded by reference to the right to self-defence, because reliance on the right to self-defence to justify occupation violating the right to self-determination and the prohibition of annexation is precluded by the necessity and proportionality requirements of self-defence, the prohibition of abuse of rights and the good faith interpretation of Article 51 of the UN Charter, as already explained in sub-chapter IV of chapter B of this paper.

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IV. Conclusion on Israeli Occupation

Israeli occupation of Palestine’s Territory breaches the jus ad bellum prohibition of the forcible acquisition of territory. It also violates Palestinians’ right to self-determination. Therefore, it is illegal. Unlawfulness of Israeli occupation cannot be excluded by reliance on the right to self-defence.

D. Conclusion

The present paper has found, similarly to the ICJ, that the unlawfulness of occupation is to be assessed under the prisms of jus ad bellum and the right to self-determination. From this perspective, occupation is illegal when it transforms into annexation and, thus, contravenes the prohibitions of the use of force and the forcible acquisition of territory. It is also unlawful when it violates the right to self-determination of the occupied people through annexation and/or serious human rights breaches. The right to self-defence cannot be invoked to remove this illegality. Application of this legal framework reveals not only the unlawfulness of Israeli occupation but can also have implications for other ongoing occupations, namely, for litigations by occupied states against occupiers.​​​​​