Revisiting the distinction between jus ad bellum and jus in bello
The fundamental distinction between jus ad bellum and jus in bello – described as “perhaps the most important principle of IHL” – is a vital bulwark against attempts to override International Humanitarian Law (IHL) by appealing to jus ad bellum considerations. It is at the heart of the principle of “equality of belligerents” which guarantees that IHL will apply to all parties to an international armed conflict, irrespective of the justification for the initial recourse to force. By the same token, jus in bello must be respected independently of any argument concerning jus ad bellum.
The separation principle, and its legal, moral, pragmatic and policy foundations, have been discussed and defended at length by scholars (see here and here). Although there have been challenges to the principle, to a great extent it has become a paradigmatic feature of contemporary legal thinking on the conduct of war.
The Advisory Opinion on the Legality of the Policies and Practices of Israel in the Occupied Palestinian Territory, Including East Jerusalem (AdvOp) raises a different – and rather underexplored – problematique in applying the separation principle: is it possible for IHL considerations to affect the legality of a conflict under the jus ad bellum? In terms of the first part of question (b) put forward by the General Assembly to the Court, how do the policies and practices of Israel in the Occupied Palestinian Territory (OPT) (namely the prolonged occupation, annexation, and settlement policy), “affect the legal status of the occupation?”
Some States appearing before the Court held that both parts of this question namely Israel’s “policies and practices” and the “legal status of the occupation” exclusively raised questions of IHL. According to this view, occupation is strictly a category of jus in bello. The issue turned, in part, on how the phrase “legal status of the occupation” was to be understood, whether, in the words of the United States, as the “fact of occupation” or rather, in the words of Switzerland, as the “lawfulness of the occupation”. The Court adopted the second view, interpreting the phrase “legal status of the occupation” to mean the legality of Israel’s “continued presence” in the occupied territory. While the AdvOp acknowledged that Israel’s policies and practices violated the jus in bello, it found that they simultaneously violated the jus ad bellum, and it was this second category of violation (together with the frustration of the Palestinian peoples’ right to self-determination) that rendered Israel’s continued presence in the OPT unlawful. This blog post intends to analyse this aspect of the Court’s opinion.
Unpacking the Court’s pronouncements on the separation principle
The Court was very careful to ground its reasoning on a strong affirmation of the separation principle. After discussing the temporary nature of occupation under jus in bello, the Court stated that “the fact that an occupation is prolonged does not in itself change its legal status under international humanitarian law” (para 109). It proceeded to state that “the legality of the Occupying Power’s presence in the occupied territory must be assessed in light of other rules” (para. 109, emphasis added). In paragraph 251, the Court states:
“[it] considers that the rules and principles of general international law and of the Charter of the United Nations on the use of force in foreign territory (jus ad bellum) have to be distinguished from the rules and principles that apply to the conduct of the occupying Power under international humanitarian law (jus in bello) …. The former rules determine the legality of the continued presence of the occupying Power in the occupied territory; while the latter continue to apply to the occupying Power, regardless of the legality or illegality of its presence. It is the former category of rules and principles regarding the use of force, together with the right of peoples to self-determination, that the Court considers to be applicable to its reply to the first part of question (b) of the request for an advisory opinion by the General Assembly (emphasis added).”
The Court concluded – by a majority of eleven votes in favor and four against – that Israel’s “continued presence” in the OPT was unlawful, in view of its violation of the prohibition of the acquisition of territory through force and the right of the Palestinian people to self-determination (para. 261).
The extent of disagreement on the application of the separation principle by the Court is reflected in the pleadings, as well as the numerous declarations, separate and dissenting opinions of the Judges.
The separation principle: Divergent views
Throughout the proceedings before the Court, States argued either explicitly or implicitly that Israel’s violation of the jus in bello – specifically the law of occupation – rendered the occupation, as a whole, unlawful. For instance, the State of Palestine, Algeria, and Egypt argued, inter alia, that the prolonged nature of the occupation and its permanent character – evidenced by Israel’s settlement policy, displacement of Palestinians, annexation of Palestinian land including East Jerusalem, and other measures aimed to alter the demographic situation – rendered the occupation itself unlawful.
On the other hand, the United States argued that the legal status of a belligerent occupation does not change if the occupation is prolonged or if illegal violations of jus in bello are committed by the Occupying Power. In the words of Marko Milanovic, “as a matter of IHL, an occupation is neither legal or illegal, just like an armed conflict is neither legal or illegal. It simply exists or not”.
In his Separate opinion, Judge Yusuf adopts the first approach. He considers Israel’s belligerent occupation of the OPT illegal by reference to both the jus in bello as well as the jus ad bellum. First, in terms of the jus in bello, he considers that an occupation that changes the characteristics of belligerent occupation under IHL (its temporary character/ protection of the interests of the occupied people/ return to sovereignty) cannot be considered lawful. This line of reasoning, which argues that Israel’s occupation of the OPT is unlawful for violating its own, intrinsic, basic tenets and principles goes beyond the Court’s findings and is defended here.
With respect to the jus ad bellum, Judge Yusuf agrees with the Court’s finding that Israel’s occupation of the OPT violates the jus ad bellum, albeit for different reasons. He observes that Israel’s excessively prolonged belligerent occupation of the OPT constitutes a continued and indefinite use of force that requires fidelity to the criteria of necessity and proportionality (notwithstanding the question of the legality of the initial recourse to force). Judge Yusuf opines, “if the prohibition of the use of force under the United Nations Charter is to be meaningful, the exception of self-defense cannot be allowed to prolong unlawfully a belligerent occupation”. To qualify Israel’s belligerent occupation as a use of force, Judge Yusuf invokes Security Council resolution 242, which required the termination of the state of belligerency and withdrawal of Israeli forces. In his view, a prolonged and indefinite use of force cannot be justified under the principles of necessity and proportionality and thus, in and of itself, constitutes a breach of the prohibition of the use of force. Similarly, according to Judges Nolte and Cleveland, the conditions of necessity and proportionality cannot be met when the occupation “becomes a vehicle for achieving annexation” (para 8).
In their Joint opinion, Judges Tomka, Abraham and Aurescu disagreed with the Court’s reasoning and conclusions. According to their view, Israel’s settlement policy and annexation of parts of the OPT, constitute violations of the jus in bello rather than the jus ad bellum as they relate to the legality of the conduct of the occupation and not its very existence. Israeli policies and practices such as annexation, population transfers, etc. are wrongful acts by reference to IHL, and they must therefore cease, but the same does not hold true of the occupation itself. According to this view, the Court erred in concluding that policies such as annexation rendered the occupation unlawful under the jus ad bellum.
The three Judges also posit that the assessment of the continued legality of the occupation (notwithstanding any assessment of its legality ab initio) would have to be made in light of Israel’s right to security, existence, and “survival”. They conclude that Israel’s security threats may justify “maintaining a certain degree of control on the occupied territory” (para. 37).
By implying that what they presume to be jus in bello considerations (the prohibition of annexation and settlement) can be overridden by the jus ad bellum considerations of “existence” and “survival”, this analysis clearly draws inspiration from the Advisory Opinion on the Threat or Use of Nuclear Weapons. In this Advisory Opinion, the Court – after having affirmed that the threat or use of nuclear weapons would be “generally” contrary to IHL – stated in the controversial paragraph 2(E) of the dispositif that it could not “conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defence, in which the very survival of a State would be at stake”. Interpretations of this Advisory Opinion that subordinate the jus in bello to the jus ad bellum by reference to the notion of “State survival” are reminiscent of the Kriegsraison doctrine which posited that obligations under the laws of armed conflict “may be displaced by urgent and overwhelming necessity”.
The Court’s Technique: Framing Israel’s policies and practices as violations of both jus ad bellum and jus in bello
To reach the conclusion that Israel’s policies and practices rendered the occupation unlawful, while maintaining a strict decoupling of the jus ad bellum from the jus in bello, the Court employs two principal methods. First, it considers that the legality of the occupation is subject to the rules of jus ad bellum, as occupation involves a continued use of force. Second, it frames Israel’s policies and practices in the conduct of the occupation as both violations of IHL and of the law on the use of force simultaneously.
Under the first proposition, the Court begins by stating that occupation, or the exercise of effective control, must be consistent with the prohibition of the acquisition of territory through force and the principle of self-determination of peoples (para 109). It observes that occupation cannot serve “as the source of title to territory or justify its acquisition by the occupying Power” (para 253). Without discussing Israel’s “security concerns” in any detail, the Court asserts – and rightly so – that such concerns “cannot override the principle of acquisition of territory through force” (para. 254).
The Court further analyses Israel’s settlement policy, and the associated transfer of parts of Israel’s civilian population into the OPT, confiscation and requisitioning of land, extension of Israeli law, forcible transfer and displacement of the Palestinian population, concluding that they constitute breaches of the relevant provisions of the Geneva Conventions and Hague Regulations (which constitute part of the jus in bello).
The Court then clarifies that these same policies and practices “are designed to remain in place indefinitely and to create irreversible effects on the ground” and are thus tantamount to annexation (para. 173). The Court thus frames these Israeli measures in terms of violations of jus ad bellum, as they evidence an intention to create a permanent Israeli presence in the OPT. In other words, Israel’s measures demonstrate corpus (effective control) and animus (intention to appropriate the territory permanently), the two pre-conditions for annexation. This is found by the Court to be “contrary to the prohibition of the use of force in international relations and its corollary, the principle of non-acquisition of territory through force” (para 179). This assertion by the Court is by no means novel and does not mean that Israel’s violations of IHL render the occupation unlawful under jus ad bellum, but rather that Israel’s measures must be considered – separately and in their own right – under the jus ad bellum.
The Court does not delve into any analysis of whether Israel’s occupation conforms to the limitations of necessity and proportionality, presumably to avoid the complex question of whether Israel’s initial and subsequent uses of force could qualify as self-defense. It is also possible that the Court found it unnecessary – as a matter of judicial economy – to address the complex and highly contextual assessment of proportionality, given that annexation is categorically prohibited under jus ad bellum. Whatever the Court’s reasons, the omission has been criticized as a gap in the Court’s reasoning and a missed opportunity to clarify the law in this area.
Concluding remarks
With the extent of disagreement shown above regarding the fundamental principle of separation of jus ad bellum and jus in bello, the Court’s pronouncements on the complete separation of these two bodies of law are a welcome contribution to a controversial theoretical debate. The Court’s technique – namely considering the legality of occupation as a matter of jus ad bellum, while framing Israel’s measures in the OPT as evidence of prohibited annexation also under jus ad bellum – served the purpose of answering the questions put forth by the GA while maintaining the separation principle. However, further elaboration by the Court could have contributed to clarifying much of the confusion and addressing the shortcomings of its own previous jurisprudence on the matter.
The author appeared on behalf of the Arab Republic of Egypt in the Advisory Opinion and is currently Legal Advisor to the Foreign Minister of the Arab Republic of Egypt. All views expressed in this blog post are the author’s own and do not represent any of the institutions to which she is affiliated.
