The Prohibition of Annexations and ICJ’s Advisory Opinion on the Occupied Palestinian Territory

The International Court of Justice issued its much-anticipated advisory opinion in Legal Consequences arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, including East Jerusalem on July 19, 2024. It is a blockbuster opinion, and a sweeping defeat for Israel. With it, the Court confidently asserts a powerful role in determining the content of international law, unhindered by concerns that powerful States might not follow its ruling. The Court decided that Israel is in violation of the law of occupation, the rights of the Palestinian people to self-determination, and international human rights law. It reached the sweeping conclusion that Israel is obligated to end its occupation as rapidly as possible, to evacuate all Israeli settlers, and to provide large-scale reparations for the damages caused by the occupation. A key building block for the entire opinion is the Court’s finding that Israel has unlawfully annexed Palestinian territory. That finding is correct, but by appearing to ground the prohibition of annexations in the prohibition of the use of force, the Court again confuses the legal basis for this norm and fails adequately to clarify what is at stake in the opinion.

Background

The UN General Assembly requested the 2024 opinion to determine inter alia the “legal consequences” arising from Israel’s “ongoing violation” of the “right of the Palestinian people to self-determination” and “from its prolonged occupation, settlement and annexation of the Palestinian territory occupied since 1967.” More than sixty states issued written statements, overwhelmingly in support of Palestine. The sometimes emotional oral proceedings lasted more than a week.

Twenty years ago this month – on July 8, 2004 – the ICJ issued an important advisory opinion holding that the wall constructed by Israel in the West Bank violates international law, including the Palestinian right to self-determination. Citing the Declaration on Principles of International Law concerning Friendly Relations and Co-operation, the Court noted in 2004 that the “the principles as to the use of force incorporated in the Charter reflect customary international law” and that “the same is true of its corollary entailing the illegality of territorial acquisition resulting from the threat or use of force.” The Court stopped short of concluding that Israel had acted to annex Palestinian territory, but it noted that the wall “could well become permanent, in which case, and notwithstanding the formal characterization of the wall by Israel, it would be tantamount to de facto annexation.”

The Court did not explain what it meant in asserting that the prohibition of annexations is a “corollary” of the general prohibition of use of force. To add to the confusion, the Court gestured in the direction of an alternative basis for prohibiting annexations: the right to self-determination. It explained in Paragraph 70 that

The Court recalls that in its Advisory Opinion on the International Status of South West Africa, speaking of mandates in general, it observed that “The Mandate was created, in the interest of the inhabitants of the territory, and of humanity in general, as an international institution with an international object – a sacred trust of civilization.” (I.C.J. Reports 1950, p. 132.) The Court also held in this regard that “two principles were considered to be of paramount importance: the principle of non- annexation and the principle that the well-being and development of . . . peoples [not yet able to govern themselves] form[ed] ‘a sacred trust of civilization’ ” (ibid., p. 131).

Confusion about the relationship between the prohibition of annexations and the regulation of the use of force also appears in contemporary scholarship. Some authors, for example, reason that annexations are unlawful because they result from an unlawful use of force. Yet that reasoning is inconsistent with the letter and spirit of the Friendly Relations Declaration, which prohibits all forcible annexations, not only those pursuant to an unlawful use of force. The dispute over Israel’s annexation of the Golan heights highlights some of the contemporary implications of this point; Israel has suggested in the context of Golan that annexations are lawful when they follow a use of force in self-defense.

It is therefore important to clarify – as we do in a forthcoming article – that the prohibition is not simply a corollary of the prohibition of the use of force. It is a distinct norm that specifically regulates title to territory, separately from the use of force. And though it is of course related to the prohibition of the use of force, what makes it so foundational to the international legal order is that it helps to sustain, and is connected to, the three central projects of international law of the past century, if not longer—relating to: (1) the use of force, (2) the self-determination of peoples, and (3) the entrenchment of state authority in defined territorial units. Because it is so central to modern international law, we have also argued that the prohibition should be recognized as a jus cogens norm, as suggested by Brazil, Palestine, and other States.

2024 Advisory Opinion & the Prohibition of Annexation

The ICJ’s 2024 Advisory Opinion concludes – as the earlier opinion had not – that Israel is in violation of the prohibition on annexations. The opinion again uses the corollary language (see para. 175 and 179), which seems to place the prohibition of annexations “in” the prohibition of the use of force. But the court also underscores the connections between annexations, the unlawful entrenchment of state authority, and the right to self-determination. Moreover, some of the reasoning makes clear that, despite the Court’s suggestion that the prohibition of annexations is part of the one on the use of force, conduct that evinces a violation of the former does not always also violate the latter.

 The Court begins by defining the term annexation in the “present context” as “the forcible acquisition by the occupying Power of the territory that it occupies, namely its integration into the territory of the occupying Power.” Annexation, the Court goes on “presupposes the intent of the occupying Power to exercise permanent control over the occupied territory.” (Para 158) With this definition, the Court discards the distinction between de jure and de facto annexations in favor of a standard that focuses on intent to assert assertions of “permanent control” over the territory. (Para 160)

The focus on the intent to exercise permanent control distinguishes annexations from violations of Article 2.4, because the intent to exercise permanent control might or might not involve a use of force in violation of Article 2.4 and the associated customary international law. To be sure, using force with the purpose of annexing territory violates the prohibition of the use of force. But the intent to exercise permanent control does not alone violate the prohibition of the use of force. And this intent might materialize in actions that violate the prohibition of annexations without also violating the prohibition of the use of force.

This distinction between the prohibition of annexations and the prohibition of the use of force is not clear in the 2024 Advisory Opinion. The Court at times conflates the two. One might therefore read its 2024 Advisory Opinion as suggesting that any conduct that qualifies as an annexation is also an unlawful use of force. The intent to exercise permanent control would, under this reading, make the conduct a violation both of Article 2.4 and of the prohibition on annexations. For example, the Court notes in paragraph 253 that an occupation involves “a continued use of force in foreign territory,” that such use of force is subject to the international legal rules governing jus ad bellum, and that “these rules prohibit the use of force to acquire territory.” These statements suggest, contrary to our argument, that annexations by definition involve unlawful uses of force. But that interpretation is not the only available one—and is, in our view, the incorrect one.

The opinion also illustrates that conduct that violates the prohibition of annexations need not involve an unlawful use of force. For example, when the Court describes the “Acts by Israel amounting to annexation,” it discusses Israel’s conduct in applying Israeli law in East Jerusalem (P.163), refusing to zone property for Palestinian construction (P. 163), impeding Palestinian efforts to obtain a building permits, creating an “inhospitable environment” for Palestinians in the area (P. 165), and instituting other measures that treat “East Jerusalem as its own territory” including measures that “regard[] Palestinians residing there as foreigners” and that require them to “hold a valid residence permit.” (P. 165). The Court also cites the processing by Israel of land ownership claims in East Jerusalem. These actions do not, on their face, amount to a use of force. They instead involve efforts to entrench Israeli state authority in territory that does not rightfully belong to it, through bureaucratic mechanisms of government. That they amount to an annexation evinces that the prohibition of annexations is, at is core, about the acquisition of territory. And though this prohibition is violated by efforts to acquire territory using force, it also can be violated by efforts to acquire territory using other mechanisms of state authority and coercion that do not, on their own, amount to a use of force in violation of Article 2.4. and the customary prohibition. In other words, the prohibition of annexations is not entirely subsumed within the prohibition of the use of force. They are separate and overlapping prohibitions. Indeed, the definition of annexations that the Court adopts brings into focus what makes it distinct, with the language “integration into the territory of the occupying power.” 

The distinction is also evident in the Court’s assessment of Israel’s conduct in the West Bank, where the Court highlights the measures that Israel has taken to entrench its own authority in territory that does not belong to it. For example, the Court mentions the integration of the “infrastructure, including the road network, with that of Israel, which results in the interlacement of the settlements in the West Bank with Israel in a contiguous area, fragmenting the remaining areas in the West Bank.” (Para 167). It also notes the application of Israeli law and the assumption of regulatory power over the West Bank. (Para 170). Again, such measures are not traditionally understood violations of the prohibition of the use of force. Indeed, characterizing them as such would be a stretch. The more accurate explanation of why they are unlawful is that they reflect a creeping effort to annex territory, through the use of national state power. They therefore violate a norm that does not depend on characterizing the conduct as a violation of Article 2.4 or customary international law. There is no need to turn a restrictive building permit regime as a use of force – it violates the prohibition of annexations, without regard to whether it also violates the prohibition of the use of force. 

Distinguishing between unlawful annexations and unlawful uses of force also avoids a doctrinal difficulty that surfaced in 2004 Wall case. Israel argued that wall did not violate international law because it was an act of self-defense, an argument that the Court rejected. But as Judge Higgins pointed out in her separate opinion, it is far from clear that the construction of a wall should be considered an act of self-defense at all – an argument the Court did not address. Under our approach one need not reach that question because the annexation violates international law whether or not it is lawful measure of self-defense and whether or not it is a use of force. The question, instead, is whether it is an exercise of “permanent control over the occupied territory”—or to use our language, an effort to entrench state authority in foreign territory with the goal of eventually acquiring it as one’s own. The lawfulness of the annexation

does not and should not depend on how the measure is characterized under the norms that govern the use of force.

This characterization also highlights that the prohibition of annexations is tied not only to the jus ad bellum but also, and just as closely, to two other core projects in international law: the entrenchment of state authority in assigned territorial units and the right of the people who live there to self-determination. Indeed, the 2024 Advisory Opinion does not read as an opinion about the jus ad bellum, except insofar as the Court itself tries to squeeze its reasoning into the jus ad bellum. The opinion is much more obviously about the territorial integrity of Palestine, as a fundamental part of its right to self-determination. The Court underscores throughout the opinion the connection between self-determination and territory, including in Para. 238, in which it concludes that “Israel’s annexation of large parts of the Occupied Palestinian Territory violates the integrity of the Occupied Palestinian Territory, as an essential element of the Palestinian people’s right to self-determination.” (see also Para 245 and others).

In these ways, the 2024 Advisory Opinion supports our claim that the prohibition of annexations is not just a corollary to limitations on the use of force. It is instead a distinct norm, one that regulates sovereign title to territory. It undergirds the prohibition on the use of force by making clear that States cannot acquire territory through force, eliminating an important cause of war.  The prohibition of annexations also contributes to a wide range of international legal norms geared towards the entrenchment of state authority in set territorial units. And, for reasons forcefully underscored by the events that gave rise to the 2024 opinion, territorial annexations constitute a fundamental violation people’s right to self-determination.

Conclusion

Situating the prohibition of annexations as a distinct norm, not subsumed entirely within the prohibition of the use of force, puts the 2024 Advisory Opinion in an analytic frame that is not only, or even primarily, about the use of force. Our analysis connects this opinion to others relating to statehood and self-determination, such as the ICJ’s cases on the Chagos Archipelago and Western Sahara. Ours also focuses attention on other possible “creeping” annexations around the world, whether by Morocco in Western Sahara, Turkey in Northern Cyprus, or China in the South China Sea and the Himalaya region. If we look only for violations of the jus ad bellum to diagnose when an annexation might be occurring, we might miss or fail adequately to take seriously all the signs of one, until it becomes a fait accompli, to the detriment of the self-determination of the peoples involved.