1. Introduction
The Charter of the United Nations (UN Charter) contains numerous provisions that have given rise to extensive academic debate regarding their interpretation and application in concrete contexts–Article 2(4) being perhaps the most prominent example.Footnote 1 In contrast, others have attracted far less attention: often forgotten, overlooked or taken for granted, their normative content remains insufficiently examined. The duty of States to cooperate with the United Nations (UN), as enshrined in Article 2(5) of the UN Charter, represents one such provision.
In a world that appears increasingly inclined to set aside multilateralism in favour of bilateralism, the paucity of discussion devoted to States’ duty to cooperate with the UN is regrettable, as this duty is essential to the effectiveness of the collective security system as well as the efficient functioning of the UN, which depends on States supporting and implementing its action. This general obligation to cooperate ‘reflects the fact that the organization is, as such, deprived of any territorial control and power’.Footnote 2
The International Court of Justice (ICJ) recognised the crucial role played by the duty to provide assistance to the UN very early in its operation, stating in the Advisory Opinion of 11 April 1949 on the Reparation for Injuries Suffered in the Service of the United Nations:
It must be noted that the effective working of the Organization – the accomplishment of its task, and the independence and effectiveness of the work of its agents – requires that these undertakings [the duty to render to the Organization “every assistance” which is accepted by the Members in Article 2, paragraph 5, of the Charter] should be strictly observed.Footnote 3
The ICJ expressly referred to Article 2(5) of the UN Charter, which reads as follows:
The Organization and its Members, in pursuit of the Purposes stated in Article 1, shall act in accordance with the following Principles. (…)
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5. All Members shall give the United Nations every assistance in any action it takes in accordance with the present Charter, and shall refrain from giving assistance to any state against which the United Nations is taking preventive or enforcement action.Footnote 4
Any international lawyer is aware of the existence of this duty. Yet, many would find it difficult to articulate its precise substance, or to point to a concrete instance of its implementation. Put differently, while knowledge of the duty is widespread, it remains largely superficial. A quick review of the UN Charter commentaries, whether in English or in French,Footnote 5 confirms this observation, with only a handful of pages devoted to Article 2(5). There does however seem to be a consensus that this duty encompasses both a positive component–the duty to cooperate–and a negative one–the obligation not to give assistance to other States against which the UN is taking preventive or enforcement action.Footnote 6
Whilst the text of this provision may appear straightforward and unambiguous at first glance, its scope has nevertheless given rise to some uncertainties within the limited scholarship that has addressed it,Footnote 7 particularly in relation to the first limb of the provision–the duty to cooperate. Indeed, there appears to be no common understanding of what the term ‘action’ entails. The debate surrounding this term is two-pronged. First, it concerns the entity from which the action must emanate: does it refer to action taken by all organs of the UN, or only that of the Security Council–the only organ endowed with the capacity to impose coercive measures on States? Second, it relates to the nature of that action: what kind of action–coercive or otherwise–is envisaged by this part of the provision? The other legal instruments that enshrine the duty of States to cooperate with the UN offer little guidance in this regard.Footnote 8
The relative neglect in the literature of the scope of Article 2(5) does not stem from an inherent lack of scholarly interest in the issues raised by this nebulous provision, nor from an exclusive preoccupation with the UN Charter’s most commented-upon provisions. This scarcity can rather be attributed to the limited practice and precedents on the matter, without which no thorough legal analysis can meaningfully be developed when a doubt persists as to the interpretation of a norm. For instance, an analysis of the Security Council or General Assembly’s resolutions indicates that, while these organs do issue general calls for cooperation or employ language similar to that of Article 2(5), they nevertheless rarely make explicit reference to it. In this regard, the repertoires of practice of the UN organs are particularly revealing: they merely refer to implicit references to Article 2(5) or references ‘having a bearing’ on the said provision,Footnote 9 with only a few exceptions. Even in cases of explicit invocations, references to Article 2(5) are made only in passing and without further elaboration.Footnote 10 Moreover, since at least 2008, the Repertoire of the Practice of the Security Council has titled the section relating to Article 2(5) as ‘Obligation under Article 2, paragraph 5, to refrain from assisting the target of enforcement action’, thereby omitting mention of the duty of cooperation.Footnote 11
This lack of practice, coupled with the sparse attention paid to this paragraph by the drafters of the UN Charter,Footnote 12 accounts for the persistence of grey areas when it comes to the precise understanding of the scope of the duty to cooperate with the UN. Recent developments on the international scene have, however, brought this dormant provision to the fore. As will be discussed in greater detail below, in 2024, Israel adopted legislation that would prevent the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) from operating. This led to debate as to whether the duty to cooperate within the meaning of Article 2(5) UN Charter also compelled Israel to cooperate with UNRWA.
This issue came before the ICJ in the context of the Advisory Opinion on the Obligations of Israel in relation to the Presence and Activities of the United Nations, Other International Organizations and Third States in and in relation to the Occupied Palestinian Territory (Obligations of Israel) Footnote 13 at the request of the UN General Assembly.Footnote 14 Although the Court did not seize the opportunity to settle the scope of Article 2(5) once and for all,Footnote 15 as elaborated upon in Section 3, the proceedings leading to the adoption of the Advisory Opinion gave rise to an unprecedented number of statements adopted by States regarding Article 2(5) UN Charter, providing considerable material which permits a significant step forward in clarifying its meaning and reach.Footnote 16 These statements provided the first comprehensive insight into States’ general understanding of the scope of this provision, and, along with the oral pleadings, form the basis of the analysis presented in this article.
Given this focus, it should be noted at the outset that, in the present author’s view, which is shared by other scholars,Footnote 17 statements submitted by States to the ICJ constitute subsequent practice relevant for the purposes of treaty interpretation. Such statements are not, however, understood as constituting subsequent practice within the meaning of Article 31(3)(b) Vienna Convention on the Law of Treaties (VCLT).Footnote 18 Indeed, for subsequent practice to qualify as an authentic means of interpretation, it must reflect the common understanding of all parties to the treaty concerned,Footnote 19 which is not the case here since not all Member States of the UN have expressed a view on the interpretation of Article 2(5). Rather, given the absence of such common understanding, the subsequent practice referred to here corresponds to ‘conduct by one or more parties in the application of the treaty’,Footnote 20 that is, a supplementary means of interpretation under Article 32 VCLT.Footnote 21 Indeed, as noted in recent doctrinal commentary on that provision, ‘[t]he subsequent practice of many States can be considered as a valid means by which to understand the meaning of a provision’,Footnote 22 notably when that meaning remains ambiguous or obscure after application of the general rule of interpretation enshrined in Article 31 VCLT.Footnote 23
This was recently confirmed by the ICJ in its Advisory Opinion on the Right to Strike under ILO Convention No. 87. Footnote 24 Previously the International Law Commission (ILC) observed that ‘subsequent practice’ for the purposes of Article 32 may take a variety of forms and is not limited to direct application of the treaty, but also encompasses all kinds of official statements concerning its meaning.Footnote 25 Furthermore, under this rule of interpretation, the fact that such practice is repeated with a certain frequency ‘is not a necessary element of the definition of the concept of “subsequent practice” in the broad sense’.Footnote 26 Accordingly, given that the written statements submitted by States to the ICJ in the course of the Advisory Opinion are ‘official’ statements providing an interpretation of Article 2(5) UN Charter, they do qualify as subsequent practice relevant to ascertaining its meaning.
At the same time, such statements cannot be divorced from the–highly–political context in which they were submitted, as is invariably the case with State practice. This holds true for both statements favouring a broad interpretation of Article 2(5) and for those advocating for a more restrictive one. While this reality calls for caution, it does not warrant disregarding such statements altogether, given that they constitute official pronouncements endorsed by States’ competent authorities, articulated in legal terms, relying on Article 2(5) explicitly and submitted before a judicial body, thereby forming relevant material informing the interpretation of this provision.
These clarifications having been made, it is now possible to turn to the substantive analysis. In order to set the parameters of the discussion at hand, the main tendencies found in the literature regarding the scope of the duty to cooperate are presented, highlighting that the prevailing interpretation among scholars is a narrow reading of Article 2(5) that confines the duty to cooperate to acts adopted by the Security Council under Chapter VII of the UN Charter (Section 2). The article then examines the positions advanced by States participating in the proceedings related to the Advisory Opinion on the Obligations of Israel. It demonstrates that the vast majority of States addressing the question of the scope of Article 2(5) advocated for an interpretation of this provision that is significantly broader than that advanced in the prevailing scholarship (Section 3). Subsequently, the article discusses how the ICJ addressed, or rather failed to address, this issue in its Advisory Opinion (Section 4). Based on the premise that States’ submissions indicate the emergence of a subsequent practice relevant for the interpretation of Article 2(5), Section 5 explores what such a broad duty to cooperate would entail in practice, illustrating its implementation in the context of the humanitarian crisis in the Gaza Strip, and more particularly regarding the provision of humanitarian assistance. This analysis leads to the conclusion that, although the duty of cooperation does not prescribe a specific course of conduct for States, it should be understood as a broad and flexible obligation of conduct–not exclusively triggered by the action of the Security Council undertaken under Chapter VII–whose implementation may take a variety of forms and which must be fulfilled in good faith.
2. The duty to cooperate prior to the Obligations of Israel Advisory Opinion
Prior to the Obligations of Israel advisory proceedings, analysis of the scope of States’ duty to cooperate with the UN was essentially limited to academic discussions. The views expressed in the literature may be grouped in three categories, which are presented below in descending order of narrowness, together with the relevant practice supporting each approach. The first and prevailing approach is to consider that the duty to cooperate is limited to measures adopted by the Security Council acting under Chapter VII of the UN Charter.Footnote 27 The rationale for this interpretation is that it is the only organ within the UN empowered to adopt measures binding upon States.Footnote 28 Thus, Article 2(5) UN Charter cannot be construed as an indirect means of imposing additional obligations on States to which they have not consented, by attributing a coercive character to acts of other organs of the UN.
In this respect, reference may be made to the few resolutions adopted by the General Assembly that explicitly mention Article 2(5), which mainly concern the question of Southern Rhodesia. In those resolutions, the General Assembly condemned the failure of States to enforce the sanctions imposed by the Security Council and characterised such failures as being contrary to the obligations assumed by those States under ‘Article 2, paragraph 5, and Article 25 of the Charter.’Footnote 29 The General Assembly thus linked the two provisions, a linkage that may be understood as an indicator that the duty to cooperate as per Article 2(5) applies only to binding resolutions adopted by the Security Council. This aligns with Helmut Philipp Aust’s observation that practice directly linked to that provision is more readily available with regard to resolutions adopted by the Security Council under Chapter VII.Footnote 30
A second approach advocates a slightly more extensive reading, according to which the term ‘any action’ referred to in Article 2(5) must be understood as a decision adopted by any organ of the UN when that organ engages in coercive action. This notion would thus encompass not only resolutions of the Security Council, but also acts of the regional arrangements or agencies mentioned in Article 53 UN Charter, as well as action undertaken by the five permanent members acting on behalf of the UN pursuant to Article 106 UN Charter.Footnote 31 In this regard, it is noteworthy that, during the brief debate held at the San Francisco Conference, the Norwegian delegate suggested clarifying that the term ‘United Nations’ found in Article 2(5) referred to the Security Council only.Footnote 32 No other delegation commented on this interpretation and the final text refers to the UN in general.Footnote 33 Proponents of this interpretation, who thus confine the duty to cooperate to actions having a coercive nature, acknowledge that only the second limb of Article 2(5)–concerning the duty not to assist–mentions the coercive character of the action, unlike the first limb which establishes the duty to cooperate. To address this obstacle, reference is made to the ICJ’s Advisory Opinion on Certain Expenses, in which it interpreted the term ‘action’ found in Article 11(2) UN Charter as referring exclusively to coercive measures.Footnote 34 In theory, on the basis of this view, nothing precludes the term ‘action’ for the purposes of Article 2(5) from likewise being confined to acts of a coercive nature, even in the absence of an explicit reference to that effect.
The last approach supports an even broader interpretation of Article 2(5), one that does not depend on the coercive nature of the action in question and that is not limited to a specific organ of the UN. This minority view distinguishes between the two limbs of the provision, emphasising that the limb prescribing the duty to cooperate does not condition the notion of ‘action’ upon any coercive character.Footnote 35 From this perspective, were the actions referred to in the first part of Article 2(5) to be limited to resolutions of the Security Council adopted under Chapter VII–whose binding character stemming from Article 25 UN Charter is undisputed–the added value of Article 2(5) would be removed. The provision would thus be rendered redundant. Moreover, as noted by Leland Goodrich, Edvard Hambro and Anne Patricia Simons, Article 2(5) has been invoked in circumstances where the action in question was not coercive in nature, namely to obtain support for UN programmes of action where no legal obligation to provide such support arose from other provisions of the UN Charter.Footnote 36
Returning to Article 11(2) UN Charter and the Advisory Opinion on Certain Expenses, it may be argued that the issue before the ICJ was substantially different from that addressed in the Advisory Opinion on the Obligations of Israel, as the question concerned matters discussed within the General Assembly that required ‘action’ to be referred to the Security Council.Footnote 37 In that context, it made sense to confine ‘action’ to coercive and enforcement measures, described by the ICJ as ‘solely within the province of the Security Council’,Footnote 38 and not consider it to include, for instance, recommendations made by the Security Council under Article 38 given that, in such a situation, the General Assembly enjoys a ‘comparable power’.Footnote 39 Interpreting ‘action’ too broadly for the purpose of Article 11 would therefore have unduly restricted the powers conferred upon the General Assembly by the same provision. Moreover, in the same Advisory Opinion, the Court did state that:
the implementation of [the General Assembly’s] recommendations for setting up commissions or other bodies involves organizational activity – action – in connection with the maintenance of international peace and security.Footnote 40
The establishment of a subsidiary organ by the General Assembly was thus regarded by the Court as constituting an ‘action’. Mention could also be made of the 2000 Brahimi Report prepared by the high-level Panel on UN Peace Operations, which asserted that States had an obligation to give every assistance, under Article 2(5) UN Charter, to fact-finding missions established by the Secretary-General.Footnote 41 In the same vein, it may be noted that the first volume of the Repertory of Practice of United Nations Organs indicated that:
The actions taken by the United Nations in accordance with the Charter are wide in scope and varied in nature. In a sense many decisions taken by the organs of the United Nations which requested Member States to co-operate in such actions may be said to bear upon Article 2 (5) ….Footnote 42
Based on this interpretation, the duty to cooperate would encompass actions of varying nature adopted by organs of the UN and would not be restricted to resolutions adopted by the Security Council.
However, this approach is a minority one, the prevailing view among scholars being the narrow interpretation confining the scope of this provision to resolutions adopted by the Security Council acting under Chapter VII, as argued by Aust.Footnote 43 However, he does acknowledge that Article 2(5) could ‘develop in the direction of a broader principle to give assistance to the UN also in contexts which are not related to Chapter VII’ and concede that the provision ‘is not entirely clear in this regard and can thus at least not stand in the way of a different reading of the provision evolving in the future’.Footnote 44
The ICJ’s Advisory Opinion on the Obligations of Israel could have constituted that turning point, catalysing the recognition of a broad duty to cooperate, given that the ICJ itself had previously opted for a broad interpretation of the provision.Footnote 45 While the Opinion did not allow for such a development as it only addressed the issue in a limited way, the proceedings leading up to it can nevertheless be considered a turning point in understanding the scope of Article 2(5). Indeed, as the next section demonstrates, almost all participants in the proceedings who addressed the issue adopted an extensive reading of this provision, thereby providing an unprecedented body of material relevant to its interpretation.
3. Emerging State practice supporting an extensive interpretation of Article 2(5)
The 2024 request to the ICJ by the General Assembly for an advisory opinion followed the receipt by the General Assembly of a letter from the Secretary-General, in which the latter expressed concern over two laws adopted by the Knesset of Israel in October 2024 which, if implemented, would de facto prevent the UNRWA from operating.Footnote 46 In a later letter addressed to both the General Assembly and Security Council, and putting forward an extensive interpretation of Article 2(5), the Secretary-General recalled that:
as a Member of the United Nations, Israel continues to be required, pursuant to Article 2, paragraph 5, of the Charter of the United Nations, to give UNRWA every assistance in any action it takes in accordance with the relevant decisions of competent principal organs adopted pursuant to the provisions of the Charter.Footnote 47
It thus comes as no surprise that Article 2(5) of the UN Charter was a recurring feature of States’ submissions to the ICJ.
In the absence of clear direction within the pertinent legal instruments and their travaux préparatoires regarding the proper interpretation of Article 2(5), and given the lack of subsequent practice by all Member States, this State practice may prove useful in determining the scope of the duty to cooperate. As noted in the introduction, the written and oral statements submitted by States to the ICJ qualify as subsequent practice in the application of Article 2(5) and may therefore serve as a supplementary means of interpretation under Article 32 VCLT.Footnote 48 It should be underlined, however, that recourse to such subsequent practice, and the evidence it provides of an emerging extensive interpretation of Article 2(5), does not necessarily imply that this interpretation has evolved from its original meaning, which is difficult to ascertain given the limited attention paid to it by the drafters. However, it is plausible that this extensive interpretation may reflect their original intention.
As noted in Section 1, until the Obligations of Israel Advisory Opinion, there was no common practice regarding the duty to cooperate, with only scattered mentions of Article 2(5) during debates before the Security CouncilFootnote 49 or General Assembly.Footnote 50 The Advisory Opinion has reshaped this landscape, giving States an unprecedented opportunity to provide their official and legal interpretation of the duty to cooperate as enshrined in Article 2(5). In total, 49 participants took part in the proceedings, including 45 States,Footnote 51 three international organisationsFootnote 52 and the Secretary-General of the UN. Among these 49 participants, 42 explicitly invoked and interpreted Article 2(5) UN Charter.Footnote 53 45 participants submitted written statements to the ICJ, and 43 participated in the public hearings.Footnote 54
The interpretation of the duty to cooperate prevailing in the written and oral submissions stands in stark contrast with the prevailing view in the literature. Of the 42 participants that interpreted this provision, 38 (comprising 34 States, all three international organisations and the Secretary-General) adopted an extensive interpretation of Article 2(5)–one that does not confine its scope to acts of a coercive nature or resolutions of the Security Council.Footnote 55 This represents 90 per cent of the total participants. Only four States favoured a narrow interpretation of the duty, according to which States are required to cooperate with the UN only in relation to resolutions adopted by the Security Council under Chapter VII UN Charter.Footnote 56 These four States are Israel, the United Kingdom (UK), the United States of America (US) and Hungary which articulated a more nuanced position, discussed later in this section.
It must, however, be underlined that States’ positions do not all display the same degree of precision in terms of legal reasoning. For instance, Jordan–which maintained that Article 2(5) imposes no limitations regarding the nature of the action concerned–supported its interpretation through references to the practice of the UN and that of States, as well as the jurisprudence of the ICJ.Footnote 57 Luxembourg, by contrast, merely asserted that Israel is required, under Article 2(5), to cooperate with all agencies of the UN, as they form integral components of the ‘UN system’.Footnote 58 The paucity of certain lines of reasoning may be attributed to a variety of reasons, ranging from the belief that the proposed interpretation is self-evident to a lack of awareness of the existing debate surrounding Article 2(5), or even to a deliberate reluctance to engage in that debate in order to avoid complex discussions. While the following analysis will primarily rely on those statements which provide substantiated reasoning, less detailed positions remain relevant insofar as they refer to Article 2(5) and indicate whether a State adopts a broad or a narrow interpretation of that provision. However, the difference in the level of engagement with the law means that it cannot be assumed that because a State has endorsed a particular approach, it necessarily subscribes to the underlying reasoning advanced by those States that have provided a more comprehensive analysis.
Be that as it may, the vast majority of participants did not limit the duty to cooperate to acts of a specific nature and/or acts adopted by a specific organ of the UN. For instance, Spain considered that:
The duty to assist and cooperate … includes the obligation to cooperate with the Organization in the application of the resolutions and other decisions adopted by its organs and bodies in accordance with the Charter and other applicable rules of the Organization ….Footnote 59
Jordan also explicitly contended that the duty to cooperate applied to any action of the UN ‘without any limitation in principle as to its nature’,Footnote 60 and, according to Palestine, without restriction as to ‘the identity of the United Nations entity taking it’.Footnote 61 China equally interpreted the term ‘action’ as encompassing enforcement measures adopted by the Security Council under Chapter VII, but not being limited to them.Footnote 62 According to the Comoros too, this ‘general obligation applies to any action taken by the Organization and is therefore not limited to Security Council resolutions’.Footnote 63
Referring to the mention of ‘any action’ in the text of Article 2(5), Belgium emphasised that nothing in the provision limits its scope to decisions made by the Security Council.Footnote 64 In the same vein, Egypt argued that the activities of UNRWA, as a subsidiary organ of the UN, constituted an action in the sense of Article 2(5),Footnote 65 and, during the public hearings, added that ‘nothing in the letter or spirit of the Charter that suggests that the term “actions” is limited only to enforcement action under Chapter VII’.Footnote 66 Bolivia noted in this regard that the ‘only requirement is that any “action” be taken “in accordance with” the Charter’.Footnote 67 Namibia defended a similar approach, insisting on the semantic differences between the two limbs of Article 2(5):
This reading of the provision is contrary to its ordinary meaning, as interpreted in accordance with Article 31 of the Vienna Convention on the Law of Treaties. The word “any action” in the first clause does not admit the additional restriction Israel asserts. This is in stark contrast with the second clause of Article 2(5), which specifically prohibits “assistance to any state against which the United Nations is taking preventive or enforcement action”. The omission of the qualifier “preventive or enforcement” in the first clause cannot be an oversight, and is crucial to the proper interpretation of Article 2 (5). In other words, the obligation of Members to assist the United Nations applies as a default, on the other hand their freedom to assist other States is exceptionally restricted, in order to achieve the objectives of preventive or enforcement action under Chapter VII it takes in accordance with the relevant decisions of competent organs adopted pursuant to the provisions of the Charter.Footnote 68
Norway rejected the interpretation according to which the duty to cooperate is limited to Security Council Chapter VII resolutions, arguing that such a reading would render the provision meaningless as it ‘would limit the scope of obligations pursuant to the Charter to those contained in Article 25 and make Article 2(5) redundant’.Footnote 69 In the same vein, Chile underlined that a ‘more restrictive interpretation would render this provision meaningless by limiting the scope of the principles of the Charter only to Article 25’.Footnote 70 Senegal argued that this interpretation gives an effet utile to the provision.Footnote 71 Saudi Arabia argued before the Court that:
‘[t]he attempt by certain States in these proceedings to limit Article 2 (5) as only applying to enforcement action by the Security Council pursuant to Chapter VII of the Charter is incorrect and contrary to this Court’s interpretation of that provision in the Reparations advisory opinion.’Footnote 72
France also mentioned the prior broad interpretation of Article 2(5) by the ICJ, and while recognising that the duty to cooperate ‘does not, of course, have the effect of conferring a binding character on the General Assembly’s recommendations’, it nevertheless considered that the general obligation must be implemented by Israel in good faith, including regarding UNRWA’s activities.Footnote 73
Furthermore, all three participating international organisations adopted a similar broad interpretation of Article 2(5).Footnote 74 For instance, the African Union argued that:
l’obligation de donner “pleine assistance dans toute action entreprise” par les Nations Unies en vertu de l’article 2, paragraphe 5, de la Charte inclut également celle de prêter pleine assistance aux actions des organes subsidiaires établis par l’Assemblée générale, comme l’UNRWA. Cette obligation couvre tant les actions normatives de l’Organisation que ses actions opérationnelles. “[T]oute action” signifie “toute action”. Dès lors, il importe peu de distinguer ici les actions qui sont prescrites dans des résolutions obligatoires en vertu de l’article 25 de la Charte, et celles qui le sont par des résolutions ayant force de recommandations.Footnote 75
Unsurprisingly, the Secretary-General reiterated his extensive interpretation of Article 2(5) which aligned with that of the majority of the participants. He thus recalled that, for the purposes of Article 2(5), ‘the “action” consists of the activities carried out by a number of United Nations entities’.Footnote 76 The Secretary-General then stated that his own practice accounts for a broad interpretation of that provision, recalling that he relied on the latter, for instance, ‘to request a State to facilitate the unhindered and safe transit of United Nations peacekeeping personnel through its territory to and from their area of operations’.Footnote 77
A plethora of additional excerpts from other participants could be cited, but the foregoing suffices to capture the broad interpretation adopted by a large majority of participants, as well as the range of arguments advanced in support of it. While not all participants indicated the legal reasoning underpinning their reading of Article 2(5), several elements can nonetheless be deducted from their submissions: (i) a textual interpretation of the terms of the provision combined with the absence of a qualifier requiring a coercive character, in contrast to the second limb of the provision; (ii) reliance on the effet utile principle, according to which limiting the duty to cooperate to resolutions adopted by the Security Council under Chapter VII would render Article 2(5) UN Charter redundant due to Article 25 of that same instrument, and (iii) reliance on existing practice–including that of the ICJ–that contradicts the narrow interpretation of the duty to cooperate.
Although the extensive interpretation clearly constitutes the prevailing view among participants to the proceedings, support for it is not unanimous. A minority of States adopted the narrow interpretation of the duty to cooperate, with frequent references to the existing literature in support of their view. In contrast with a statement made by its representative before the General Assembly in 1966 regarding the initiation by Ethiopia and Liberia of a case before the ICJ regarding South West Africa,Footnote 78 Israel adopted a narrower interpretation of Article 2(5):
the obligation of assistance laid down in Article 2, paragraph 5 does not encompass all action undertaken by each and every organ or agency of the UN, but is limited to enforcement action taken by the UN Security Council under Chapter VII of the Charter. This interpretation is consistent with the general structure of the Charter and the respective functions assigned by it to the organs of the Organization, and is supported by the drafting history of the provision.Footnote 79
Also referring to the respective powers of each organ of the UN, the US followed a similar approach limiting the scope of the duty to cooperate to the action taken by the Security Council acting under Chapter VII:
Consistent with the functions and powers of the principal organs set forth in the Charter, Article 2(5) is limited in that “action” can be taken only by the Security Council acting under Chapter VII.
Article 2(5) does not encompass recommendations issued by other organs of the United Nations, such as the General Assembly. To the contrary, interpreting Article 2(5) as imposing a positive obligation on U.N. Member States to assist the organization in connection with a resolution of any of its organs absent legally binding action by the Security Council would constitute a dramatic expansion of the powers of U.N. organs. Such an expansion is not reflected in the language of the Charter and would be inconsistent with the Security Council’s primary responsibility for the maintenance of international peace and security.Footnote 80
Furthermore, in the oral phase, the US pointed out that nowhere in the UN Charter are the powers of the General Assembly qualified as ‘actions’.Footnote 81 The UK also suggested the ICJ should not endorse an extensive reading of Article 2(5) by interpreting ‘action’ as encompassing anything other than the actions of the Security Council. The UK maintained that such an approach would fail to reflect past practice and the drafting history of that provision, and risk imposing ‘unspecified and potentially unlimited obligations on Members’ and calling into question ‘the carefully defined system of competences of the principal organs as laid down in the Charter’.Footnote 82
While Hungary could be included among the States adopting a narrow interpretation of the duty, its reasoning differs from the others in that it did not expressly assert that the scope of Article 2(5) is limited solely to action undertaken by the Security Council under Chapter VII. Rather, Hungary limited its discussion to the requirement that the action be taken in accordance with the UN Charter:
The obligations arising from Article 2 thus have to be interpreted consistently taking into account the actions of the UN, its specialized agencies and subsidiary bodies as well. Thus when paragraph 5 of Article of the Charter stipulates that “[a]ll Members shall give the United Nations every assistance in any action it takes in accordance with the present Charter …” it is clear that a limitation to this obligation is included. The Organization is obliged to take actions in accordance with the Charter, thus if actions of the Organization were to be found contrary to the Charter the Member in question cannot be expected to give the assistance required by the said Article.Footnote 83
Hungary then went on to discuss allegations concerning UNRWA’s failure to maintain neutrality and its ties to terrorism.Footnote 84 Hungary’s position could thus be interpreted as implicitly acknowledging that the duty to cooperate does apply to actions taken by organs other than the Security Council.
In conclusion, the Advisory Opinion proceedings provide ample evidence of the emergence of a subsequent practice according to which the duty to cooperate with the UN is not limited to measures adopted by the Security Council acting under Chapter VII, and thus does not constitute a mere repetition of Article 25 UN Charter. This outcome is quite striking, as it implies that a number of States would accept being bound by a broad duty to cooperate with the UN. Yet, as next section shows, the ICJ did not–at least not explicitly–endorse the broad interpretation of Article 2(5), but opted for caution and–as is often the case when compromise is required–ultimately articulated an ambiguous line of reasoning.
4. The duty to cooperate before the ICJ: A missed opportunity
Given the uncertainty that surrounds the scope of the duty to cooperate and the number of States that submitted observations on the duty in their written submissions, the ICJ could have seized the opportunity offered to bring the debate to a close by clarifying the exact scope of the duty to cooperate under Article 2(5) UN Charter. Some of the Court’s Judges regretted its cautious approach, arguing that it should have put forward a broad interpretation of that provision, as it appears to have done in 1949 in the Reparation for Injuries Advisory Opinion.Footnote 85 In discussing the need of protection for the agents of the UN in that Advisory Opinion, the ICJ stated that:
For this purpose, the Members of the Organization have entered into certain undertakings, some of which are in the Charter and others in complementary agreements. The content of these undertakings need not be described here; but the Court must stress the importance of the duty to render to the Organization “every assistance” which is accepted by the Members in Article 2, paragraph 5, of the Charter.Footnote 86
As Judge Xue recalled in her separate opinion in Obligations of Israel, ‘[t]he “undertakings” mentioned in this statement were definitely not limited to the decisions of the Security Council. For a large part, they were actions taken by the General Assembly’.Footnote 87 However, the ICJ refrained from addressing the issue directly in the Advisory Opinion and offered a reasoning filled with ambiguitiesFootnote 88–a reasoning, in the words of Judge Charlesworth, that leaves the reader ‘wondering what such a reading might entail’,Footnote 89 and which could potentially be read as supporting either the narrow or the broad interpretation of Article 2(5).
The relevant passage of the Advisory Opinion starts by recalling that Member States have an obligation to cooperate with the UN and that such an obligation is of paramount importance for the effective functioning of the organisation.Footnote 90 After reproducing the text of Article 2(5), the ICJ went on to add that this provision ‘must be read together with the provisions of the Charter relating to the powers of various organs of the United Nations’.Footnote 91 However, the Court did not elaborate on the implications of this qualification. On the one hand, proponents of the narrow interpretation of Article 2(5) could argue that, by mentioning the distribution of powers under the UN Charter, the Court made an implicit reference to the argument according to which the duty to cooperate is only triggered by the action of the Security Council acting under Chapter VII. On the other hand, those favouring a broad interpretation of the duty to cooperate could understand this reference to the powers of the UN organs as no more than an element to be considered when determining, in accordance with the final part of Article 2(5), whether the relevant action is taken in accordance with the UN Charter.
The rest of the reasoning is of little help in determining the ICJ’s understanding of the scope of the duty to cooperate. Indeed, it does not define the term ‘any action’ for the purposes of Article 2(5), leaving this part of the Advisory Opinion open to interpretation. The wording used seems to indicate that this is an intentional silence; the Court never once ascribes the duty to cooperate to a specific organ of the UN. There is no mention of a duty to cooperate ‘with the Security Council’, ‘with the General Assembly’, or ‘with UNRWA’–the organ whose activities were the object of the matter before the Court. The Advisory Opinion only mentions the duty to cooperate ‘with the United Nations’ in general–which could be interpreted as an indicator that, according to the ICJ, the Security Council is not the only organ capable of triggering the duty to cooperate.
This reading of the ICJ’s reasoning is corroborated by the last paragraphs of the section devoted to the obligation to cooperate with the UN. Indeed, a few elements seem to reveal that the ICJ did, in fact, apply the duty to cooperate to actions undertaken by organs other than the Security Council:
Furthermore, the Court notes that UNRWA, as a subsidiary organ of the United Nations, has been entrusted by the General Assembly to provide direct relief and work programmes for Palestine refugees. It cannot carry out such a mandate effectively without having direct access to the population in the Occupied Palestinian Territory. This is particularly true given the crucial role that UNRWA has been playing since October 2023. In the view of the Court, Israel is not entitled to withhold its co-operation with the United Nations by unilaterally deciding on the presence and activities of United Nations entities in and in relation to the Occupied Palestinian Territory, subject to paragraph 184 below. …
Based on the foregoing, Israel, as a Member of the United Nations, is under an obligation to co-operate in good faith with the United Nations, in particular by virtue of Article 2, paragraphs 2 and 5, of the Charter. Pursuant to this obligation, Israel may not obstruct the functions of the United Nations and must provide every assistance in any action taken by the Organization in accordance with the Charter in and in relation to the Occupied Palestinian Territory, subject to paragraph 184 below.Footnote 92
By recalling that UNRWA is a subsidiary organ of the UN established by the General Assembly,Footnote 93 and stating that Israel is not entitled to withhold its cooperation with the UN in this respect and remains bound by the obligation to cooperate under Article 2(5), the ICJ appears to have regarded the activities of UNRWA as constituting ‘action’ by the UN capable of triggering States’ duty to cooperate. Indeed, at no point does the ICJ refer to a resolution of the Security Council in its reasoning; the action of UNRWA appears to be sufficient to discuss the respect, or lack thereof, by Israel of its duty to cooperate with the UN.
The separate and dissenting opinions and declarations elaborated by the judges of the ICJ and attached to the Advisory Opinion explain the caution evident in the Court’s reasoning. It could not provide an explicit clarification as to the scope of the duty to cooperate because its judges disagreed on that specific point. As a matter of fact, while only a few paragraphs address this issue in the Advisory Opinion, Article 2(5) UN Charter is a frequently recurring element in the opinions and declarations appended to the decision–Judge Charlesworth even dedicated her declaration to this question alone. In sum, here again, both the narrow and broad interpretation of the duty to cooperate are endorsed.
In support of the broad interpretation, in his partially dissenting opinion, Judge Gómez Robledo contends that ‘the Court has adopted a timid and excessively formalistic approach that has no basis in reality, by failing to specify that this duty of cooperation also entails, under certain circumstances, the obligation to lend assistance to the General Assembly in any action undertaken by it’.Footnote 94 Convinced that that the duty to cooperate is not limited to the action of the Security Council, nor to binding obligations sensu stricto,Footnote 95 Judge Gómez Robledo affirms that the duty to cooperate ‘extends beyond the strict institutional division of functions among the principal organs of the United Nations’.Footnote 96 Supporting a broad reading of Article 2(5), Judge Charlesworth shares this frustration and regrets the opacity of the reasoning of the Court. Judge Xue also endorses the extensive interpretation of the duty to cooperate in her separate opinion, for a variety of reasons, including the ordinary meaning of the terms of Article 2(5), the potential redundance of Article 25 UN Charter,Footnote 97 as well as the attainment of the purposes of the UN.Footnote 98 All three judges argue that the Court failed to engage adequately with its previous–and seemingly broad–interpretation of the duty to cooperate in the Reparation for Injuries Advisory Opinion.Footnote 99
However, in support of a narrow interpretation, Judges Abraham and Cleveland reject a broad interpretation of Article 2(5) and warn that an extensive reading would ‘transform non-binding “actions” of United Nations organs into legally binding ones and frustrate the core distinction in the distribution of powers under the Charter’.Footnote 100 They suggest that the term ‘any action’ cannot but refer to actions that are already legally binding as such. In other words, the duty to cooperate would only be triggered when there is an existing legally binding obligation that can then be coupled with the duty to cooperate.Footnote 101 In line with this approach, Vice-President Sebutinde, in her separate opinion, notes that limiting the scope of Article 2(5) to enforcement measures adopted by the Security Council acting under Chapter VII is consistent with the assignment of specific functions to specific organs under the UN Charter.Footnote 102
Consequently, the Advisory Opinion leaves the reader with more questions than they had previously. This could have been avoided had the ICJ relied on the prevailing interpretation advanced in the written and oral submissions of States discussed in Section 3. Detailed consideration of this useful material–barely mentioned by the ICJ–would have enabled it to address the specific scope of the duty to cooperate on the basis of subsequent practice relevant for the interpretation of Article 2(5).
Although it may be contended that the scope of the duty to cooperate is not limited to the action of the Security Council, this interpretation alone is not sufficient to grasp its practical implications. What lessons, then, can be drawn from the Advisory Opinion in this regard? Article 2(5) cannot, indeed, be interpreted as creating new legal obligations upon States; nor can it serve as an indirect means of circumventing the principle of consent so as to confer binding force upon acts that are, in nature, non-binding. How can such a limit be reconciled with the broad interpretation of Article 2(5) that extends the duty to cooperate to the action of organs other than the Security Council? The next section explores this tension, identifying what the duty to cooperate with the UN actually entails by illustrating its implementation in the context of the delivery of humanitarian aid in the Gaza Strip.
5. Enforcing the duty to cooperate: A flexible obligation of means
In his commentary on Article 2(5), Aust concludes that the interpretation according to which the first limb of Article 2(5) refers exclusively to action undertaken by the Security Council under Chapter VII UN Charter constitutes the reading that best reflects the existing practice at the time regarding this provision.Footnote 103 However, he nonetheless recognises that Article 2(5) ‘might develop in the direction of a broad principle’,Footnote 104 conceding that the provision may be understood as enshrining a general obligation of loyal cooperation between the UN and its members.Footnote 105 He suggests that a possible way of conceiving the duty to cooperate would be to distinguish, on the one hand, an ‘inner core’ attached to the functions exercised by the UN in the context of Chapter VII and, on the other hand, a ‘wider circle’, within which common positions among States could be established regarding the interactions between the UN and Member States.Footnote 106
Building on this line of reasoning, it is argued that States’ duty to cooperate with the UN could be conceived as a broad obligation of conduct that must be fulfilled in good faith,Footnote 107 governing the relationship between, on the one side, Member States, and, on the other side, UN organs when the latter act in pursuit of the objectives set out in the UN Charter and in accordance with the powers conferred upon them by it. At a minimum, this obligation would entail a negative dimension, requiring States not to impede the action undertaken by the organ in question. When it comes to the positive aspects of its implementation, the duty to cooperate would take various forms depending on the circumstances of each case, including whether the State required to cooperate is a third State with respect to the situation at issue, the means available to the State, as well as the existence of related obligations that are, in themselves, legally binding. In this sense, the duty to cooperate may be understood as a spectrum of conduct, requiring varying degrees of proactive engagement on the part of the State whose assistance is under consideration.
As Members of the UN, States must also implement this duty in good faith in accordance with Article 2(2) UN Charter:
All Members, in order to ensure to all of them the rights and benefits resulting from membership, shall fulfill in good faith the obligations assumed by them in accordance with the present Charter.Footnote 108
The linkage between the duty to cooperate and the principle of good faith is important when discussing the implementation and interpretation of this duty, as good faith ‘is apt to contain the discretionary power of States parties under treaty provisions which grant them some leeway.’Footnote 109 More specifically, as noted by Robert Kolb, the requirement of good faith is of particular significance in a ‘legal sub-system like UN law’ given that ‘the sovereignty of States blunts the capacity for strong collective actions’.Footnote 110 However, the duty to cooperate should not be conflated with the principle of good faith, as the latter is ‘a “modality” in which States shall fulfil other obligations.’Footnote 111
This abstract and theoretical account of the implementation of the duty to cooperate is better understood when applied to a concrete case. In this regard, the humanitarian crisis in the Gaza StripFootnote 112 once again provides a useful illustration: that of the obligation of States to cooperate with the UN, and more particularly UNRWA, in the provision of humanitarian assistance. This is a matter of direct concern to the UN given that, among its purposes Article 1(3) UN Charter expressly refers to ‘international co-operation in solving international problems of an economic, social, cultural, or humanitarian character, and in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion’.Footnote 113 Article 55 could also be cited, according to which:
With a view to the creation of conditions of stability and well-being which are necessary for peaceful and friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, the United Nations shall promote:
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1. higher standards of living, full employment, and conditions of economic and social progress and development;
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2. solutions of international economic, social, health, and related problems; and international cultural and educational cooperation; and
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3. universal respect for, and observance of, human rights and fundamental freedoms for all without distinction as to race, sex, language, or religion.Footnote 114
It thus comes as no surprise that, as the ICJ acknowledged in Obligations of Israel,Footnote 115 the UN became involved in the provision of humanitarian assistance to Palestinians at an early stage, mostly acting through UNRWA–a subsidiary organ of the General Assembly created pursuant to Article 22 UN Charter.Footnote 116 Since the resumption of hostilities in October 2023, UNRWA’s activities in the Gaza Strip have been significantly undermined, and in some respects curtailed, as a result of various measures adopted by a series of States. This includes, for instance, the decision of States such as the US, Germany and the UK to suspend the funding allocated to it.Footnote 117 Israel adopted legislation aimed at preventing the presence and activities of UNRWA, including within the occupied Palestinian territory.Footnote 118 These laws gave rise to serious concern on the part of the Secretary-General and the General Assembly, which responded by adopting the resolution requesting the Advisory Opinion emphasising ‘the importance of upholding multilateralism and the central role of the United Nations in the multilateral system’.Footnote 119
While these measures also raise questions in relation to the privileges and immunities of UN personnel,Footnote 120 this article focuses on the identification of the substance of the duty to cooperate, addressing the implications of this duty for the relationship between States and UNRWA. Regarding Israel, the duty to cooperate with UNRWA implies that, first, Israel cannot adopt measures preventing UNRWA from operating in the occupied Palestinian territory, and second, that it must assist UNRWA in the delivery of humanitarian aid there when such an operation is conducted by the latter in accordance with its mandate. This is the interpretation of the duty in Article 2(5) adopted by the Secretary-General in his identical letters addressed to the General Assembly and the Security CouncilFootnote 121 and also to Israel’s Ambassador to the UN.Footnote 122 This is also the interpretation advanced by various States in their written submissions to the ICJ, including, for instance, Malaysia, which argued that:
Israel’s attempt, through the adoption of the two laws already discussed, to deprive the Organisation of legal capacity in the territory that Israel controls, its attempt to take over UNRWA premises and property, and the attacks on such premises and property in the context of security or military operations are nothing but the latest iterations of a consistent pattern of conduct in defiance of the obligation of good faith cooperation with the United Nations.Footnote 123
The Maldives also contended that Israel, by virtue of Article 2(5) UN Charter, is bound to cooperate with UNRWA:
UNRWA is a subsidiary organ of the UN established by the UN General Assembly in accordance with Article 22 of the UN Charter, and is therefore an “integral part” of the UN. …
The activities of UNRWA pursuant to this General Assembly mandate, including its humanitarian operations with respect to the supply of water, are a form of “action” taken by the UN in accordance with the UN Charter within the meaning of Article 2(5) of the Charter. Pursuant to that provision, Israel therefore has an obligation to “give … every assistance” to this action. The phrase “every assistance” is clearly a broad one, requiring both a duty to take positive action and an obligation to refrain from interfering with the UN’s actions, as circumstances require.Footnote 124
The duty of cooperation thus requires Israel to provide UNRWA with full assistance, to the extent of the means available to it, so as to enable UNRWA to effectively carry out its humanitarian aid activities. Does this imply that Article 2(5) gives rise to new legal obligations incumbent upon Israel by conferring a binding character to the General Assembly resolution establishing UNRWA? The answer must clearly be in the negative. As formulated by Judge Charlesworth in her declaration attached to the Advisory Opinion, ‘an obligation to “give every assistance” is of a different nature to an obligation to comply’.Footnote 125 In other words, the duty to cooperate in the sense of Article 2(5) does not imply that, for instance, Israel has to accept the presence of UNRWA on its own territory. This was rightly and clearly recalled by the ICJ.Footnote 126 But this does not mean that Israel can completely disregard UNRWA, or prevent it from operating. In other words, while Israel was under no obligation to accept the presence of UNRWA on its territory, once it consented to its presence, the duty to cooperate meant that it could no longer exercise unfettered discretion in its dealings with this agency. A level of proactive cooperation may be required from Israel, because it acts as an Occupying Power and is bound by existing obligations in the Fourth Geneva Convention relating to the provision of humanitarian assistance.Footnote 127 According to Article 55, Israel must ensure the food and medical supplies of the occupied population.Footnote 128 If the population is inadequately supplied, the Occupying Power–and all Contracting Parties–must permit and facilitate the free passage of relief schemes undertaken by States or impartial humanitarian organisations.Footnote 129 Article 2(5) then provides an overarching framework for understanding and applying the relevant international humanitarian law obligations insofar as they pertain to the relationship between Israel and the UN.
By way of illustration, as an Occupying Power, Israel has a right of control over relief schemes entering the occupied territory and may impose technical arrangements in that regard in order to ensure that the consignments are intended for the benefit of the population.Footnote 130 If the relief scheme is implemented by UNRWA, however, Israel will not enjoy the same degree of discretion in exercising this control as it would with another entity, for instance by unilaterally preventing the delivery of relief consignments on the basis of a suspicion that they are not intended for the benefit of the population. Rather, Israel would first have to cooperate with UNRWA with a view to clarifying the matter, and it could even be argued that the issue should be brought to the UN. It is in this sense that the duty to cooperate informs the interpretation of concrete rules of International Humanitarian Law. Ultimately, this reflects the idea of loyalty underpinning the duty to cooperate, as advanced by Aust,Footnote 131 and implies that Israel cannot treat UNRWA in the same manner as other entities when exercising the prerogatives conferred upon it by International Humanitarian Law. This is precisely because Israel has a duty to cooperate with UNRWA, an agency that was created by an international organisation–the UN–of which Israel is a Member State.
It is also interesting to note that the obligation to allow free passage of humanitarian assistance mentioned above can also be found in various orders issued by the ICJ in the context of the case initiated by South Africa against Israel regarding the Application of the Convention on the Prevention and Punishment of the Crime of Genocide in the Gaza Strip. In its Order of 26 January 2025, the Court indicated that:
The State of Israel shall take immediate and effective measures to enable the provision of urgently needed basic services and humanitarian assistance to address the adverse conditions of life faced by Palestinians in the Gaza Strip.Footnote 132
In a later Order, the Court recalled that such a provision of humanitarian aid must be conducted in full cooperation with the UN:
Take all necessary and effective measures to ensure, without delay, in full co-operation with the United Nations, the unhindered provision at scale by all concerned of urgently needed basic services and humanitarian assistance, including food, water, electricity, fuel, shelter, clothing, hygiene and sanitation requirements, as well as medical supplies and medical care to Palestinians throughout Gaza, including by increasing the capacity and number of land crossing points and maintaining them open for as long as necessary.Footnote 133
Pursuant to the ICJ’s case law, orders for provisional measures are binding on the parties to which they are addressed.Footnote 134 These obligations are also reflected in resolutions adopted by the Security Council. Reference may be made, in particular, to Resolution 2712 of 15 November 2023:
The Security Council … calls for urgent and extended humanitarian pauses and corridors throughout the Gaza Strip for a sufficient number of days to enable, consistent with international humanitarian law, the full, rapid, safe, and unhindered humanitarian access for United Nations humanitarian agencies and their implementing partners, the International Committee of the Red Cross and other impartial humanitarian organizations, to facilitate the continuous, sufficient and unhindered provision of essential goods and services important to the well-being of civilians, especially children, throughout the Gaza Strip, including water, electricity, fuel, food, and medical supplies, as well as emergency repairs to essential infrastructure, and to enable urgent rescue and recovery efforts, including for missing children in damaged and destroyed buildings, and including the medical evacuation of sick or injured children and their care givers.Footnote 135
Thus, as a Member State of the UN and an Occupying Power, Israel must cooperate with UN organs providing humanitarian assistance pursuant to Article 2(5) UN Charter, while International Humanitarian Law informs the scope of such cooperation. Other States are also bound by the duty to cooperate, but as they are not Occupying Powers, the implementation of this duty will materialise differently. This is evident from Article 55 UN Charter, which lists a series of purposes of the UN relevant for the humanitarian crisis in the Gaza Strip including solutions of international economic, social, health, and related problems and universal respect for human rights.Footnote 136 And pursuant to Article 56, ‘[a]ll Members pledge themselves to take joint and separate action in co-operation with the Organization for the achievement of the purposes set forth in Article 55’.Footnote 137 Accordingly, if one accepts that the duty to cooperate with the UN acting in accordance with the Charter constitutes an obligation of conduct, it may be argued that other States also have a role to play in the field of humanitarian assistance.
On this point, Malaysia contends in its written statement that:
With respect to ‘action’ taken under Article 56, it is worth noting that Article 2(5) of the UN Charter provides, in part, that ‘[a]ll Members shall give the United Nations every assistance in any action it takes in accordance with the present Charter’. The text is open to an interpretation that allows for an obligation of Member States to assist the Organisation in action such as that referred to in Article 56 of the Charter. Footnote 138
This assistance will not look the same for third States as it does for Israel. Yet, as recalled by Bolivia, this assistance can still take various forms: political, financial, or logistical.Footnote 139 Malaysia’s written statement is compelling to understand the variety of measures encompassed by the duty of cooperation. It gives concrete examples of how Malaysia has cooperated with the UN in order to assist it in the achievement of its purposes. For instance, explaining its decision to submit a written statement in relation to the Advisory Opinion, Malaysia indicated that it was guided by its obligation to cooperate with the UN.Footnote 140 Further, Malaysia specified that it has:
undertaken diplomatic efforts to ensure delivery of humanitarian and development aid to the Occupied Palestinian Territory, and has cooperated with the United Nations, and in particular the United Nations Relief and Works Agency for Palestine Refugees in the Near East (hereinafter: UNRWA), including through making voluntary financial contributions. Footnote 141
There are thus various ways of cooperating in good faith with the UN which, in themselves, do not give rise to new legal obligations for States. That is not to suggest that States are required to intervene on the ground to ensure that UNRWA is able to carry out its activities, nor that measures contrary to this such as the suspension of funding, taken in isolation, would amount to an internationally wrongful act. Rather, the purpose of the duty is to guide States in their conduct vis-à-vis UNRWA and in the domain of humanitarian assistance in general.
It may also be noted that the examples outlined above correspond to the expectations articulated by the General Assembly with respect to third States in the field of humanitarian assistance and its delivery in the Gaza Strip. In its resolution ES-10/25, the General Assembly stated it:
Calls upon the Agency to fully implement its high-level action plan for the implementation of the 50 recommendations of the Independent Review of Mechanisms and Procedures to Ensure Adherence by UNRWA to the Humanitarian Principle of Neutrality (Colonna Report), and welcomes the commitment affirmed by the Secretary-General and the Agency to fully implement the recommendations, and urges Member States to provide the necessary political and financial support to enable timely, effective and accelerated implementation. …
Appeals to States and organizations for voluntary contributions to the Agency, including multi-year funding agreements and an increase in such contributions where possible, in particular for the programme budget of the Agency, as well as for its emergency, recovery and reconstruction programmes as set out in its appeals and response plans, to support the mandate of the Agency, to alleviate its recurrent underfunding, to mitigate imminent risks to its core and emergency programming and to prevent the interruption of essential assistance to the Palestine refugees and the dire repercussions of any such interruption.Footnote 142
In sum, States’ duty to assist the UN constitutes an obligation of conduct, that must be fulfilled in good faith, encompassing both positive and negative dimensions, and must be understood in the particular context, the scope of its implementation depending on the action at issue and on the State concerned. It constitutes a duty that States must constantly bear in mind when interacting with an organ of the UN. Naturally, it is easier to require specific conduct from a State where a pre-existing, legally binding obligation that is more directly applicable to the particular situation can be identified. However, the existence of a duty to cooperate is not contingent upon a specific obligation, but the scope of what may be expected from the State will vary according to such obligations. As noted by Judge Gómez Robledo in his partially dissenting opinion:
States’ duty of co-operation is not confined to binding obligations in the strict sense. When the action required goes beyond this, that is, it requires States to take measures that do not necessarily derive from a specific obligation, then it is founded on a broader framework, specifically that which derives from the general duty to co-operate with the Organization. Even though States enjoy a certain latitude in interpreting this obligation, the obligation to co-operate remains an extensive one, since it is an integral part of the very object and purpose of the United Nations.Footnote 143
In that sense, the duty to cooperate serves as a constant reminder that, even in the absence of a specific legal obligation, States retain a certain margin of manoeuvre to act by virtue of this general duty, which operates as an overarching framework for other potential obligations.
6. Conclusion
The Obligations of Israel Advisory Opinion brought discussion on States’ duty to cooperate with the UN under Article 2(5) UN Charter out from the confines of purely scholarly debate for the first time. Until the advisory proceedings, engaging seriously with this duty constituted an endeavour marked by a degree of unease. In the absence of thorough discussions at the time of the UN Charter’s adoption or substantial and consistent practice on the part of international actors, analyses of the content of the duty to cooperate remained largely inconclusive, superficial and limited in scope. Despite its fundamental importance, it had previously proven difficult to lift the veil on the question: what ‘action’ is contemplated by Article 2(5) or, rather, which actions of the UN trigger the duty to cooperate? The prevailing view in the existing literature confined this duty to action of the Security Council undertaken under Chapter VII of the UN Charter, while nevertheless leaving open the possibility of a broader interpretation in light of subsequent developments on the international scene.
The humanitarian crisis in the Gaza Strip has reshaped the landscape by bringing the duty to cooperate under Article 2(5) UN Charter into sharp practical focus. Among the issues that have arisen is the relationship between States, Israel in particular, and UNRWA in the exercise of its functions in the field of humanitarian assistance. From the outset, the Secretary-General set the tone by invoking Article 2(5) to remind Israel of its duty to cooperate with the UN, including UNRWA. This was followed by the Obligations of Israel advisory proceedings, in which the duty to cooperate as enshrined in Article 2(5) emerged as a recurrent theme in the written and oral submissions of the participants. Against this background, it could have been expected that the ICJ would seize the opportunity to precisely determine the scope of the duty to cooperate. However, as this article has highlighted, the Court failed to do so and, instead, articulated an ambiguous position which, far from putting an end to the debates surrounding Article 2(5), risks creating even more uncertainty. This is particularly regrettable given that a large majority of participants to the procedure supported a broad reading of the duty to cooperate, and an explicit endorsement of this by the ICJ would have been especially welcome at a time when the collective security system is increasingly being eroded.
This broad interpretation of the duty to cooperate does not confine its scope to acts of the Security Council, but also encompasses acts undertaken by various organs of the UN as long as they are acting in conformity with the UN Charter. This article has argued that the submissions to the ICJ evidence the emergence of State practice supporting an extensive interpretation of Article 2(5) UN Charter that are relevant for interpreting this provision pursuant to Article 32 VCLT. While it is true that these statements were made in a highly specific and politically charged context, and that only time will tell whether such an interpretation will be reiterated in other situations, they nevertheless constitute an unprecedented opportunity to discern the prevailing interpretation of Article 2(5) among States.
Based on the analysis of these submissions, it is suggested that the duty to cooperate is better understood as an obligation of conduct, comprising both a negative and a positive dimension, guiding States when interacting with organs of the UN. This duty should be fulfilled in good faith, in accordance with Article 2(2) UN Charter–echoing Aust’s understanding of the duty to cooperate as an ‘obligation of loyalty’.Footnote 144 Regarding its implementation, the article proposed viewing the forms of the duty as a spectrum, with the exact level of cooperation being context-specific. At least with regard to its positive dimension, the degree of cooperation will thus vary according to the means of the State concerned, or the existence of other pre-existing and more specific legal obligations. It has also been shown that the duty to cooperate constitutes an incentive for States to (re)act, for instance by sponsoring and voting for a resolution requesting an advisory opinion to the ICJ. In that sense, the duty to cooperate should not be conceived as an undue burden imposed upon States, but rather as an enabling framework and a tool at the disposal of States to calibrate their conduct in accordance with the objectives of the UN.
As a final observation, the significance of States’ submissions must be clearly emphasised, particularly given that their impact might extend beyond the specific Advisory Opinion. Despite usually being protective of their sovereignty, almost all the States participating in the proceedings interpreted Article 2(5) of the Charter as enshrining a broad duty to cooperate. This constitutes a particularly strong–and seemingly overlooked–signal that, contrary to what may be assumed, States continue to place confidence in the UN and remain willing to contribute to the achievement of its purposes through a variety of, and at times innovative, means. This serves as a much needed and timely reminder at a moment when the UN, having just celebrated its eightieth anniversary, is facing increasing criticism and scepticism. In this context, the endorsement by States of a broad duty to cooperate appears to be a meaningful and thoughtful gift.
Acknowledgments
The author is grateful to Professors Maurizio Arcari and Jean-Christophe Martin for organising the EMOJIE Summer School in 2025, during which the author had the opportunity to present initial reflections on the subject. The author would also like to thank Professor Vaios Koutroulis for valuable discussions on this topic, as well as the two anonymous reviewers for their insightful comments.
