2.1. Articulating a category of international legal subjects

Every legal system comprises legal persons that serve as focal points for the application of the system’s rules, that is, legal constructs in which rights, obligations and capacities are vested.Footnote ¹⁷ For a legal person to exist, it is sufficient that it be addressed by at least one rule of the system. But rather than creating legal persons in an ad hoc manner, legal systems typically establish categories of subjects for whom a bundle of default entitlements and duties accrue. Consider the category of ‘natural persons’ in domestic law. To legal subjects forming part of that category—typically human beings born alive—a vast range of default rights, obligations and capacities apply under public law and private law. The legal concept of ‘natural person’ is, therefore, juridical-operative in the sense that it structures the scope ratione personae of the application of rules of domestic law without requiring each rule to address specific individuals.

In international law, the legal concept of ‘State’ performs an equivalent juridical-operative function. Instead of ascribing rights, obligations and capacities to the various polities of the world on a case-by-case basis, the rules of general international law apply to States as a category. And so does the legal concept of international organization, though its emergence and development are more recent and less certain.

The term ‘international organization’ appeared in scholarship as early as the second half of the nineteenth century, but only grew in currency in the 1920s.Footnote ¹⁸ It was originally employed rather loosely, referring both to an ideal of world government or administration and to the actual institutional arrangements that brought States together.Footnote ¹⁹ The terminology was tentative because international lawyers, still operating under the orthodoxy that States were the only subjects of international law, struggled to make sense of the intergovernmental entities that States were beginning to use in earnest. For example, writing in 1919 Lassa Oppenheim described the League of Nations as a sui generis legal person.Footnote ²⁰

In the post-Second World War period, however, the notion of international organizations as a category of legal subjects started to coalesce. This development is evident not only in scholarship but also in international practice. For example, the Vienna Convention on the Law of Treaties (VCLT) purports to apply ‘to any treaty which is the constituent instrument of an international organization and to any treaty adopted within an international organization’.Footnote ²¹ And in later codification projects, the ILC turned to the task of identifying general rules that apply to international organizations as such, particularly the Vienna Convention on the Law of Treaties between States and International Organizations and between International Organizations (VCLT 1986) and ARIO. In a similar vein, when giving an opinion to the World Health Organization in 1980, the International Court of Justice (ICJ) stated that ‘[i]nternational organizations are subjects of international law and, as such, are bound by any obligations incumbent upon them under general rules of international law, under their constitutions or under international agreements to which they are parties’.Footnote ²²

The concept of international organization has thus been serving the juridical-operative function of articulating a category of international legal subjects, to the members of which a certain bundle of default rights, obligations and capacities accrue. As such, it defines the scope ratione personae of the application of rules of international law and plays a crucial allocative role when collective action is taken on the international plane.Footnote ²³ International organizations are ‘layered’ or ‘corporate’ persons, in that they are created by other legal subjects (mainly States).Footnote ²⁴ When a group of States takes collective action, the question arises to whom that action must be attributed and whose rights and obligations will be triggered. If the group is composed of States acting in their own name, international law will attribute the action to the States themselves, and it will be their own rights and obligations that will be implicated. But if the group acts through a separate legal subject, international law will also recognise that entity as a focal point for attribution of the relevant conduct and for the application of rules.Footnote ²⁵ In this scenario, questions will arise about the position of the members vis-à-vis the rights and obligations of the organization and what kind of responsibility they may bear for the organization’s conduct qua members. And here the concept of international organization has seemingly evolved to fulfil another allocative function: that of effecting a legal separation between the agents and the principals, thereby limiting the latter’s liability for collective action taken through the former. Article 34 VCLT 1986 states that a treaty does not create rights or obligations for States or international organizations who are not party to it without their consent, whereas Article 62 ARIO takes the position that members are not in principle responsible for the internationally wrongful acts of their organization.Footnote ²⁶

If the concept is to fulfil this juridical-operative function and play those ensuing allocative roles, it follows that international legal personality must be an essential element of it. It is not unusual, though, to find in the literature the suggestion that it goes beyond ‘formal intergovernmental organizations’ set up as subjects of international law. For example, Golia and Peters have suggested that ‘non-personalized actors should not be left out’ of the legal concept of international organization when they display the ‘power to shape the normative situation of humans’ and if they ‘possess a sufficient degree of autonomy’.Footnote ²⁷ They refer to the much-debated case of the Organization for Security and Co-operation in Europe (OSCE), which boasts a robust institutional arrangement even though it remains unclear whether the States that created it intend for it to operate as a legal person on the international plane.Footnote ²⁸ The suggestion is that, either way, the OSCE must be viewed as an international organization.

Is that line of reasoning persuasive? To assess it, one must consider what a legal concept of international organization that does not articulate a category of subjects of international law would achieve. To recall, in the case of an inter-State network without separate international legal personality, international law will attribute acts performed by the network to the participating States themselves. It will be their individual and collective rights and obligations that will be at stake. Thus, the resulting scenario may involve multiple potential claimants and respondents but to which the normal rules of State responsibility and other legal regimes addressing States will remain applicable.Footnote ²⁹ In that scenario, deploying the concept of international organization adds nothing to the analysis from the perspective of public international law. It is at best a symbolic move, for it is of no consequence for the application of any of the rules of the system. Consider also the scenario where there is a legal challenge to the action of a non-governmental entity constituted under domestic law, but which shows the ‘power to shape the normative situation of humans’ and possesses ‘a sufficient degree of autonomy’. For international law to address that entity, it needs to enjoy international legal personality.

The insight that there is little, if any, utility in a legal concept of international organization that does not comprise the element of international legal personality is borne out by the case law of the ICJ and the work of the ILC. In Reparation for Injuries, the ICJ was asked to advise on whether the United Nations (UN) could bring an international claim against a non-Member State that had injured one of its officials. That led the Court to enquire into whether, ‘in the international sphere’, the UN had ‘such a nature as involves the capacity to bring an international claim’. A preliminary question was whether the UN had been given ‘such a position that it possesses, in regard to its Members, rights which it is entitled to ask them to respect’—in other words, whether it possessed ‘international personality’ in the sense that it was an ‘entity capable of availing itself of obligations incumbent upon its Members’.Footnote ³⁰ That stands to reason: if the UN were not an international legal person, the question would rather be whether the Member States could jointly bring a claim qua a group of States.

Similarly, when it prepared the ARIO, the ILC treated legal personality ‘distinct from that of [the] member states’ as ‘a precondition of the international responsibility’ of an international organization.Footnote ³¹ As Special Rapporteur Giorgio Gaja said, ‘one [had] to start from the premise that responsibility under international law may arise only for a subject of international law’, for ‘international law cannot impose on an entity “primary” obligations or “secondary” obligations in case of a breach of one of the “primary” obligations unless that entity has [international] legal personality’.Footnote ³² The same assumption underlies the Conclusions on the Identification of Customary International Law, where the Commission acknowledged that ‘[i]n certain cases, the practice of international organizations also contributes to the formation, or expression, of rules of customary international law’.Footnote ³³ To be able to contribute to the formation of custom through its own practice, an international organization must have a legal identity that is distinct from that of the members. Even in the context of the codification of the law of treaties involving international organizations, when the ILC refrained from elaborating on any questions relating to legal status,Footnote ³⁴ Special Rapporteur Paul Reuter conceded that ‘it followed clearly from the draft articles that an international organization could be a subject of international law’.Footnote ³⁵ After all, how could an entity that does not possess international legal personality conclude an international treaty in its own name?

That does not mean that tricky cases will not exist, as with the OSCE, where politics has led to a situation of legal ambiguity. But if an international claim were brought to challenge an OSCE action, a decision would need to be made as to whether the conduct is imputable to the OSCE because it is an international organization with its own separate legal personality, or whether the conduct is attributable to all or some of the 57 participating countries because it is not. That would be the litmus test for the determination of the status of the OSCE. If the OSCE were referred to as an international organization regardless of the answer, that would involve using a concept that serves no legal purpose.

Golia and Peters refer to the interesting example of the Bank for International Settlement (BIS), which was incorporated as a company limited by shares in Switzerland following the conclusion of a treaty by six States in 1930. In 2002, an Arbitral Tribunal established under the auspices of the Permanent Court of Arbitration concluded that the BIS was an international organization.Footnote ³⁶ Golia and Peters suggest that the Tribunal’s conclusion was correct because, ‘despite its private form’, the BIS performs its functions ‘in the public interest’.Footnote ³⁷ But the gist of the award is not so much that a private law entity that performs public functions of international concern can be legally classified as an international organization but, rather, that the BIS was intended, and set up in a way that ultimately allows it, to possess international legal personality. The Tribunal observed that ‘the rather complicated manner in which the Bank was established must be seen in light of the stage of development of international law in 1930’, when ‘some of the parties to the treaty had doubts as to whether a treaty could establish under public international law a company limited by shares and whether such a company could be generally recognized’; that the parties had ‘made clear that … the company could not be subjected to Swiss law’; and that three headquarters agreements concluded by the BIS expressly affirmed its international legal personality.Footnote ³⁸ Thus, even if the BIS exemplifies an entity created ‘with an international treaty sitting … only in the background’, as Golia and Peters describe it, what the reasoning of the Tribunal does is to bring the treaty to the foreground. The BIS was deemed an international organization not in application of a broader legal concept but, because, despite its peculiarities, it is a subject of international law.

While international legal personality appears to be an essential element of a legally meaningful concept of international organization, it does not exhaust the concept. It can be said that every international organization is an international legal person, but not every international legal person qualifies as an international organization. Rather, international organizations are legal persons belonging to a category of subjects to whom a bundle of default rights, obligations and capacities accrues under international law. What this bundle comprises, and how it is acquired, is addressed by the concept of international organization in its law-stating functions, to which the next section turns.

2.2. Stating rules governing the acquisition and legal consequences of a status

The concept of international organization serves as a shorthand for the rules governing the legal status of members falling within the category of subjects it articulates. Concepts creating a legal status stand for a ‘complex legal condition of rights and duties’ that determine how the status is acquired (and lost) and what the legal effects of the acquisition (and loss) of the status are.Footnote ³⁹ Take the legal concept of the State. It encapsulates the rules relating to the acquisition of statehood and the rules laying down the legal consequences that follow. In the broadest terms, acquisition of statehood takes place when a territorial community under government achieves independence in circumstances where no fundamental rules of international law have been breached.Footnote ⁴⁰ Once that status is acquired, the entity enjoys the full range of rights, obligations and capacities that States have, including juridical equality, territorial and personal jurisdiction, and the duty not to intervene in the internal affairs of other States coercively.Footnote ⁴¹ The concept of international organization must likewise stand for the rules that determine how an international organization comes into being and what default bundle of rights, obligations and capacities follows.

As regards the acquisition of the status of international organization, the main legal requirement, as Finn Seyersted put it, appears to be the creation of ‘[i]nternational organs… which are not all subject to the authority of any other organized community except that of the participating communities acting jointly through their representatives on such organs’.Footnote ⁴² Or, in the words of the Schermers and Blokker treatise, the establishment of a ‘form of cooperation: (1) founded on an international agreement; (2) having at least one organ with a will of its own; (3) established under international law’.Footnote ⁴³ That basic institutional architecture enables the organization to exist, on the international plane, as a legal subject distinct from its members—distinct in that it is formally capable of acting in its own name without being subject to the domestic jurisdiction of its members or third States.

Though there may be agreement on the basics, the rules governing the acquisition of the status of international organization, and their application to borderline cases, inevitably raise unresolved questions. There is, for example, the longstanding debate over the extent to which the creation of an international organization depends on the (subjective) intention of the members. It is widely accepted that an international organization may exist without the members designating it as such. It is equally clear that no international organization will be established against the wishes of the members.Footnote ⁴⁴

Another question is whether the rules on acquisition of status comprise any substantive—as opposed to institutional—requirements. It is not uncommon to find, in the literature or even in judicial decisions, the claim or intimation that acting in the public interest is an essential element of the legal concept of international organization.Footnote ⁴⁵ But that line of reasoning must overcome at least two challenges. The first is that international law remains rather permissive when it comes to what States can do, individually or collectively. It can be convincingly argued that an international organization may not be established for the purpose of breaching jus cogens rules, but beyond that States enjoy considerable latitude in creating and using international organizations. The second challenge is that defining ‘public interest’ in this domain is far from straightforward. The activities of organizations possessing (or aspiring to) universal membership might plausibly be described as in the public interest. However, the same cannot be readily said of the activities of regional international organizations.Footnote ⁴⁶ By way of illustration, the main goal of the Organization of the Petroleum Exporting Countries is ‘the coordination and unification of the petroleum policies of Member Countries and the determination of the best means for safeguarding their interests, individually and collectively’.Footnote ⁴⁷ Even organizations like the European Union (EU), which may have a genuine interest in promoting the global public interest in certain areas, are designed to prioritise the interest of their member States and their populations.Footnote ⁴⁸

Yet, speaking of the ‘public interest’ helps illuminate what may well be a shared attribute of international organizations, though it might be more accurate to speak instead of ‘objectives of common interest’, as Michel Virally did,Footnote ⁴⁹ or of ‘activities which, if pursued by a single State, would be jure imperii activities’, in the more precise terminology of Ignaz Seidl-Hohenveldern.Footnote ⁵⁰ Seidl-Hohenveldern’s terminology is not dissimilar to an early proposal made by Special Rapporteur Gaja to the ILC, which would have restricted the definition of international organization to entities that ‘[exercise] in [their] own capacity certain governmental functions’.Footnote ⁵¹ Indeed, it is difficult to see why States would set up an international organization to pursue goals of a purely private or commercial nature, with no element of public purpose or regulation whatsoever. Even the International Tin Council (ITC), which was sued in the UK by firms and banks seeking recovery of debts arising from its tin-purchasing and other contractual trading activities, was established to pursue public objectives relating to the regulation of the tin market, including the prevention of unemployment.Footnote ⁵² But it remains an open question whether the nature of an organization’s activities can serve as a meaningful legal requirement for the acquisition of status, or whether it should instead be understood as a potential element of a broader political-philosophical concept of international organization.Footnote ⁵³ Whatever the answer, the nature of the entity’s activities may still be relevant to the legal analysis, as it can clarify whether those creating the organization intended to fulfil, and in fact did fulfil, the formal institutional criteria over which there is agreement. When pronouncing on the status of the BIS, for example, the Arbitral Tribunal relied on the bank’s ‘quintessentially public international’ functions to support its finding that the Member States had intended to create, and did in fact create, an international organization rather than a mere private Swiss company.Footnote ⁵⁴

In addition to rules that create status, the legal concept of international organization must also encapsulate the rules that lay down the legal consequences flowing from that status. It must, in other words, serve as a shorthand for the default rights, obligations and capacities that international organizations enjoy qua members of a category of subjects of international law. This includes a range of issues on which academic commentary and international practice continue to focus, most notably the extent to which international organizations are subject to the rules of general international law that bind States.Footnote ⁵⁵ The general direction of travel has been to extend to international organizations the default rules that apply to States: VCLT 1986 and ARIO largely reflect the general rules on the law of treaties and the law of international responsibility that apply to States, respectively. Although the practice of domestic courts is conflicted in the field of immunities, there is a strong case for the proposition that international organizations and their officials enjoy (relative) immunity from the domestic jurisdiction of States.Footnote ⁵⁶

These issues are extensive enough to fill half a syllabus for a course on the law of international organizations and therefore cannot be discussed in detail here. It is worth emphasising two points. The first is that the real significance of being an international organization lies in the bundle of default rights, obligations and capacities flowing from membership in the category. Consider entities such as the vaccine alliance GAVI, or the International Committee of the Red Cross (ICRC), which do not straightforwardly meet the requirements for acquisition of status discussed above. These entities are international legal persons to the extent that they are addressed by rules contained in international treaties.Footnote ⁵⁷ If they were to be additionally viewed as international organizations, this would entail that they are not only beneficiaries of those treaty rules but also members of a category of legal subjects enjoying legal autonomy on the international plane, potentially capable of accessing customary rules such as treaty-making capacity and jurisdictional immunities. This is part of what Katerina Linos and Kristina Daugirdas have described as the ‘distinctive advantages’ of being a ‘paradigmatic international organization’ in a recent study of how informal networks, initially lauded as a more flexible form of international cooperation, have institutionalised over time.Footnote ⁵⁸

The second point is that the legal concept of international organization is dynamic rather than static, for it states rules of positive law that are in a constant process of clarification, development and contestation. Compared even to the law that applies to States, the law of international organizations remains somewhat rudimentary and inevitably contains incomplete rules. It follows that the concept needs to be updated whenever rules governing the acquisition of, or the legal consequences flowing from, that status emerge, change or are refined. This does not mean that the concept lacks any degree of stability; rather, it is a work in progress and can be profitably dissected and improved over time.

In this connection, when one considers the relationship between the concept of international organization and positive international law, it should be clear that the meaningful question to ask is not ‘is the concept part of general international law?’, but rather ‘is the concept being used in a way that correctly states rules of general international law in force?’. Law-stating concepts can be said to be rooted in positive law, but only in the sense that whether they correctly state valid rules provides the yardstick by which their accuracy is measured. This, in turn, circumscribes the role that such concepts play in legal reasoning. In his classic piece ‘Tû-Tû’, Alf Ross recognises the utility of legal concepts while disabusing the reader of the notion that they have a meaning—or an import—going beyond the rules that they state. Commenting on the concept of ‘right’, Ross observes that the ‘terminology is associated for us with more or less indefinite ideas that a right is a power of an incorporeal nature, a kind of inner, invisible dominion over the object of the right’—ideas that ‘bear a considerable structural resemblance to primitive magic thought concerning the invocation of supernatural powers which in turn are converted into factual effects’.Footnote ⁵⁹ Whatever one’s instinctive reactions may be, Ross seeks to demonstrate that the concept of right, as with any legal concept, is but ‘a tool for the technique of presentation serving exclusively systematic ends’.Footnote ⁶⁰ Those deploying the legal concept of international organization must be likewise careful to resist the influence of magical thinking. In principle, calling an entity an international organization can mean no more than saying that, under general international law, it meets the requirements for acquiring that status and that the corresponding legal consequences thereby come into play.Footnote ⁶¹

2.3. Of the concept and definitions of international organization

Definitions of international organization are often adopted in scholarship and international practice. How do such definitions relate to the legal concept of international organization? In theory, a definition could attempt to apprehend the concept in full, providing a comprehensive statement of the rules for which the concept is a shorthand. But that is seldom practical or desirable, as definitions are typically adopted for specific purposes.Footnote ⁶² That is why legal definitions typically correspond to slices of legal concepts.

It must then be asked which aspects of the concept a definition of international organization must seek to capture. Definitions of international organizations within ILC projects have thus far been adopted to elucidate the scope ratione personae of the rules, conclusions or guidelines being prepared. International organizations were defined as ‘intergovernmental organizations’ in the VCLT, the Vienna Convention on the Representation of States in their Relations with International Organizations of a Universal Character, and VCLT 1986 to clarify that the rules being proposed did not apply to non-governmental organizations established under domestic law.Footnote ⁶³ When the ILC turned to the question of the responsibility of international organizations, it concluded that a more robust definition would be useful to convey that only that category of international legal persons could be liable on the international plane according to the rules being proposed. International organizations were thus defined as ‘established by a treaty or other instrument governed by international law and possessing [their] own international legal personality’.Footnote ⁶⁴

To recall, in the most recent ILC debate on definitions, in the context of its study on the settlement of disputes to which international organizations are party, Special Rapporteur Reinisch questioned the received wisdom from ARIO, on the view that international legal personality is ‘more a consequence than a defining element of being an international organization’.Footnote ⁶⁵ He proposed instead that the definition emphasise the possession of ‘at least one organ capable of expressing a will distinct from that of its members’.Footnote ⁶⁶

Possession of organs capable of expressing a distinct will and legal personality are linked, but speak to different functions and aspects of the legal concept of international organization. Possession of organs capable of expressing a distinct will is an element of the law-stating function, as it refers to a requirement for the acquisition of status. International legal personality doubles as an element of the law-stating function, insofar as it refers to a consequence flowing from the acquisition of status (as proposed by Rapporteur Reinisch), and as an element of the juridical-operative function, insofar as it is essential for the concept to articulate a category of international legal subjects and effect the allocation of conduct and responsibility among entities acting on the international plane. In short, the concept comprises both elements.

Which of the elements, then, should be emphasised for the purposes of determining the scope ratione personae of a study on international dispute settlement? To appraise this question, it is important, first, to highlight that none of the ILC studies thus far has attempted to deal comprehensively with the rules that govern the acquisition of the status of international organization. The ILC’s approach, rather, has been to identify the elements of the legal concept that seemed most relevant (and palatable for the relevant stakeholders, especially States sitting in the Sixth Committee of the UN General Assembly) for clarifying who the addressees of the codification projects being pursued were. Whether a set of guidelines on dispute settlement needs to go further than previous projects in explaining how an entity acquires the status of international organization is thus doubtful.

Moreover, when one considers the topic of dispute settlement, it is necessary to ponder which element seems most meaningful. Is it possession of organs expressing a distinct will or international legal personality? As Mathias Forteau noted in the ILC’s debate:

Indeed, when the ICJ was asked whether the UN could make a claim against a non-Member State, thus engaging in dispute settlement, the question that the Court proceeded to answer was whether the UN had international legal personality, not whether it possessed an organ capable of expressing a will of its own (even if its analysis implies a positive answer to the latter question). Martins Paparinskis has further observed that:

He continued:

As the plenary debates were coming to a close, Penelope Ridings made the pragmatic point that ‘States and international organizations unfamiliar with the theory of international organizations might be confused by the phrase “expressing a will distinct from that of its members”’.Footnote ⁷⁰ She added that ‘[i]t was important that the definition should be understandable on its own terms and easy to implement in practice’ and that ‘possession by an international organization of international legal personality’, being ‘an element that was commonly seen as central to the concept of an international organization’, should be favoured.Footnote ⁷¹

Including the element of international legal personality in a definition of international organizations for a study on dispute settlement thus makes sense. It does not follow, however, that this definition should not include the element of possession of an organ with a distinct will, which does indeed constitute an important requirement for the acquisition of status. It is thus fortunate that the ILC decided to split the difference, provisionally adopting the following definition:

This formulation improves upon the ARIO definition by adding an additional element which may be useful to an interpreter dealing with a borderline case.

In this respect, the case law of the ICJ is instructive. In Reparation for Injuries, the Court pointed not only to the organs with which the Member States had equipped the UN but also to the fact that the UN concluded treaties and was the beneficiary of the Convention on the Privileges and Immunities of the United Nations.Footnote ⁷³ Sixty years later, in Pulp Mills, the Court concluded that Comisión Administradora del Río Uruguay, the commission Argentina and Uruguay had created to manage the Uruguay River, was an international organization not only because it was given ‘the necessary resources… and facilities’ needed to perform its functions (including a secretariat and subsidiary bodies) but also because the parties endowed it with ‘legal personality’ and the staff’s secretariat enjoyed privileges and immunities.Footnote ⁷⁴ This confirms that both the elements required for the acquisition of the status of international organizations and the elements that flow from the acquisition of that status can serve as indicia that an entity ‘occupies a position in certain respects in detachment of its members’Footnote ⁷⁵ and ‘has a permanent existence of its own’.Footnote ⁷⁶ Just as an international organization can be identified from its constitutive elements, one can similarly deduce its status from the elements it manifests.

3.1. Applying and developing institutional law

As personified legal entities under international law, international organizations possess their own internal legal system, commonly known as the ‘rules of the organization’ or ‘institutional law’.Footnote ⁷⁷ Institutional law comprises ‘the constituent instruments, decisions, resolutions and other acts of the international organization adopted in accordance with those instruments, and established practice of the organization’.Footnote ⁷⁸ While it finds its ultimate source in international law, in that it derives its validity from an organization’s constituent treaty, institutional law can enjoy significant autonomy from the system of international law that applies to States and international organizations on the international plane.Footnote ⁷⁹ This is because, other than the outer limits posed by jus cogens rules, the international legal system as it stands does not seek to determine the content of institutional law. It leaves to institutional law the determination of how treaty and customary rules binding the organization on the international plane are to be received on the institutional plane. In this respect, the relations between international law and institutional law bear a resemblance to the relations between international law and domestic law.Footnote ⁸⁰

The functions that the international law concept of international organization will perform in any given system of institutional law will thus depend on how it is incorporated. At least three such functions can be identified. First, the concept is needed if the organs of an international organization are to comply, acting under institutional law, with international obligations owed to other international organizations. For example, the Court of Justice of the EU (CJEU) has explicitly recognised that the EU ‘must respect international law in the exercise of its powers’, with the implication that rules of customary international law are ‘binding upon the [Union] institutions and form part of the [Union] legal order’, and that they can even serve as a ground for the annulment of regulations in cases where the Council of the EU has ‘made manifest errors of assessment concerning the conditions for applying those rules’.Footnote ⁸¹ If an organization is to respect the rights of its peers, it has to consider and deploy the international law concept of international organization faithfully.

Second, and relatedly, the concept will play a role whenever a rule of institutional law purports to apply or otherwise refers to other international organizations. For example, the General Data Protection Regulation (GDPR) adopted by the EU prescribes that ‘[a] transfer of personal data to a third country or an international organization may [only] take place where the [EU] Commission has decided that the third country … or the international organization in question ensures an adequate level of protection’.Footnote ⁸² The international law concept of international organization is necessary for EU institutions to identify the entities to which that rule applies. In cases like this, it will perform some of its usual juridical-operative functions (providing a reason to treat the international organization as a legal person for the purposes of applying institutional law) and law-stating functions (providing a gateway for international rights and obligations that the relevant organs will enforce).

That said, close attention must be paid to instances in which institutional law makes atypical use of the concept. For example, Article 4(a) of Annex VII of the EU Staff Regulations envisages the payment of an expatriation allowance to officials required to move to a European State which is neither their State of nationality nor the State where they habitually resided in the preceding five years, with an exception being made for ‘circumstances arising from work done for another State or for an international organization’.Footnote ⁸³ In Vardakas v Commission,Footnote ⁸⁴ the claimant had worked in Brussels for seven years for the European Committee on Standardization (ECS), an international non-profit association under Belgian law that gathers the national standardisation bodies of over 30 European countries. Following his recruitment to work in Brussels for the European Commission, he claimed that he was entitled to the expatriation allowance because, as per Article 4(a), he had been living in Belgium in ‘circumstances arising from work done … for an international organization’. The Court of First Instance (now known as the General Court) thus had to determine whether the ECS qualified as an international organization for the purpose of applying Article 4(a).

To do so, the Court considered two opinions that had been issued by the Board of Heads of Administration: the first, given in 1975, interpreting the term ‘international organization’ as entities that were ‘international in composition’, engaging in an ‘international activity of general interest’, ‘permanent in nature and [having] an organized structure’ and ‘non-profit-making’; the second, given in 1986, interpreting the term as comprising entities ‘created by States or by an organization which itself was created by States’.Footnote ⁸⁵ While the first interpretation would include the ECS, the second excluded it. In the proceedings, the European Commission argued, convincingly, that the 1986 opinion was ‘consistent with the definition of a public international organization and judiciously reflects the special legal rules governing public international organizations and the special situation of their officials’.Footnote ⁸⁶ The Court, however, favoured the 1975 opinion on grounds of institutional law, turning its mind to ‘the legislature’s intention’ and the purpose of the expatriation allowance.Footnote ⁸⁷

In an aside, the Court confirmed the undisputed view that the ECS would qualify as an international organization under the 1975 opinion, stating that:

Whether or not recognition by States and other international organizations is indeed an element for the acquisition of the status of international organization under international law, the reasoning of the Court suggests a special understanding of what qualifies as an international organization for the purpose of applying the EU Staff Regulations rather than an attempt to apply the international law concept of international organization.

Third, the concept may come into play whenever an organization seeks to rely on its international legal status to determine or develop its own internal rules. In that sense, it performs a distinctive juridical-operative function that Frändberg would describe as ‘methodological’ and ‘programmatic’, for it ends up serving as a ‘[principle] guiding legal reasoning, and especially interpretative reasoning’.Footnote ⁸⁹ That happens, in the first instance, when the general law stemming from the system of public international law is invoked to fill gaps in the special regime of institutional law.Footnote ⁹⁰ As the ILC explained in its Conclusions on the Fragmentation of International Law, whenever ‘a matter not regulated by special law [arises] in the institutions charged to administer it… the relevant general law will apply’.Footnote ⁹¹

It is often the case, for example, that institutional law will not comprise a comprehensive liability regime, and that breaches of institutional law may thus be addressed under the rules governing the responsibility of international organizations for wrongful acts on the international plane. In a case concerning the dismissal of the speaker of the East African Legislative Assembly (EALA) of the East African Community (EAC), the EAC Court of Justice ruled as follows:

Relatedly, the concept may play a role in the interpretation of institutional law for the purpose of identifying the powers of an organization and its various organs. A challenge that presents itself often in practice is that constituent instruments are silent on the permissibility of certain courses of action. For example, when the ICJ was asked whether the UN had the power to bring an international claim for injuries suffered by one of its officials, or whether the General Assembly had the competence to create an administrative tribunal empowered to give binding judgments, there were no specific provisions in the UN Charter which the Court could interpret. The Court thus articulated the influential approach to the effective interpretation of constituent instruments known as the ‘implied powers’ doctrine. As the Court put it in a later judgment:

A form of implied power argument that is directly connected with the international law concept of international organization is the inference that because an organization enjoys a capacity or right on the international plane it must also be entitled to exercise that capacity or right as a matter of institutional law. Finn Seyersted has argued that ‘no constitutional provisions are necessary to establish the capacity of an intergovernmental organization to perform those “sovereign” or international acts which States have an inherent capacity to perform’.Footnote ⁹⁴ Rather, he considers that ‘[c]onstitutional provisions have only negative significance, inasmuch as they may preclude the exercise of such capacities in certain respects’.Footnote ⁹⁵ If ‘capacity’ is understood as ‘competence under institutional law’, the argument is that an international organization should be presumed to have the constitutional authorisation to perform any acts on the international plane that international law entitles it to perform qua an international organization.

That was seemingly the ICJ’s starting point in Reparation for Injuries. The Court’s reasoning comprised two steps. First, it found that the UN was ‘a subject of international law and capable of possessing international rights and duties’ and with ‘the capacity to maintain its rights by international claims’.Footnote ⁹⁶ Second, it concluded that ‘[t]he functions of the Organization are of such a character that they could not be effectively discharged if they involved the concurrent action, on the international plane, of fifty-eight or more Foreign Offices’ and that ‘the Members have endowed the Organization with capacity to bring international claims when necessitated by the discharge of its functions’.Footnote ⁹⁷ The Court thus appeared to have borrowed from public international law to make a finding of institutional law.

3.2. Competing self-understandings of the character of institutional law

The extent to which the international law concept of international organization, in its juridical-operative programmatic function, will bear upon the interpretation, application and development of institutional law may be affected by the emergence of endogenous concepts of international organization within institutional law itself. When any given entity understands itself as belonging to the international legal category of international organizations, looking to international law to solve problems of institutional law, or even borrowing rules and procedures from other organizations, may be treated as a constitutionally sound approach. Nevertheless, international organizations may develop competing self-understandings when they become highly specialised, ambitious or institutionally robust.

Consider the notions of the ‘classical international organization’ and ‘supranational international organization’ in academic commentary. In Michel Virally’s account, while classical international organizations (or ‘international organizations properly so-called’) serve the purpose of co-operation (‘to encourage and promote the harmonization and co-ordination of their member States’ policies and lines of conduct’), supranational international organizations serve the purpose of integration (‘bringing their member States closer together by taking over certain functions’).Footnote ⁹⁸ The institutional law of supranational organizations is given the moniker of ‘supranational law’, that is, ‘regional law (1) with a certain level of autonomy vis-à-vis the national and international legal orders (2) regulating transversally a cross-section of different areas (3) and steering legal, economic, and/or political integration of its Member States’.Footnote ⁹⁹

The main example of a supranational organization is the EU, given its extensive competences (some of which are exclusive) and its uniquely robust and developed internal legal order. EU law stands out from the institutional law of other international organizations, such as the African Union or the Organization of American States, not only for its coverage but also for how it intertwines with the domestic laws of Member States through the doctrines of ‘primacy’ and ‘direct effect’, according to which EU law takes precedence over domestic law and may directly create rights for individuals.Footnote ¹⁰⁰ Those doctrines both inform and are undergirded by a strong conception of the autonomy of EU law. As the CJEU said in the Achmea case, ‘autonomy of EU law with respect both to the law of the Member States and to international law is justified by the essential characteristics of the EU and its law’.Footnote ¹⁰¹

Because of its supranational features, the EU maintains an ambivalent position as to its status as an international organization. As the European Commission argued in a comment submitted to the ILC:

This is why the international law concept of international organization does not play a significant role in the interpretation and development of EU law. For one, the CJEU does not refer to the ‘rules’ of interpretation of the VCLT to construe the EU’s constitutive treaties.Footnote ¹⁰³ Moreover, it has excluded the application of the regime of countermeasures articulated in the ARSIWA and the ARIO between the EU and its Member States.Footnote ¹⁰⁴ It has also invoked the autonomy of EU law as a ground to annul regulations adopted for the implementation of Security Council resolutions that EU States are bound by under Articles 25 and 103 UN Charter,Footnote ¹⁰⁵ and to block a 2013 draft agreement which would have enabled the EU to join the European Convention on Human Rights.Footnote ¹⁰⁶ As noted above, the CJEU accepts that the EU ‘must respect international law in the exercise of its powers’ and that rules of customary international law ‘are binding upon the [Union] institutions and form part of the [Union] legal order’.Footnote ¹⁰⁷ Yet, as Paul Gragl observed in a survey of the CJEU’s case law, ‘[a]s long as [customary international law] can be used in the interests of EU law this is not a problem; but once it potentially becomes a threat to it, any further invocation or application of substantive [customary] rules ends’.Footnote ¹⁰⁸

While the EU remains unique, some of the supranational features and self-understanding that have evolved in its practice (in particular through the case law of the CJEU) have been extended to other international organizations that pursue economic and political integration. Both the Court of Justice of the Andean Community and the Court of Justice of the Eurasian Economic Union have articulated doctrines of autonomy, primacy and direct effect inspired by the case law of the CJEU.Footnote ¹⁰⁹ The comparative practice of those organizations can be a source of legal innovation, which raises an important question: might a legal concept of ‘supranational international organization’, endogenous to institutional law, also be emerging on the international plane, which could compete with (or otherwise qualify) the international law concept of international organization?

Some authors have been impressed by the increasingly common use of the term ‘regional integration economic organization’ (REIO) in treaty law, for the purpose of allowing the EU and similar organizations to join certain multilateral agreements.Footnote ¹¹⁰ In its interventions in the debates on the codification of the responsibility of international organizations, the European Commission sought to persuade the ILC to adopt a special rule of attribution of conduct for REIOs. The argument was that due to the level of integration between the EU and its Member States, acts performed by the Member States in the implementation of EU law should be attributed to the EU alone.Footnote ¹¹¹ While there was some authority for this position, the ILC concluded that it was ‘preferable at the current stage of judicial developments not to assume that a special rule has come into existence to [that] effect’.Footnote ¹¹² Thus far, the concepts of supranational international organization and REIO have seemingly remained confined to institutional law and a few treaties.Footnote ¹¹³ Over time, however, the practice of those organizations may well lead to more far-reaching developments, and the possibility that international law may come to recognise different categories of international organizations, each captured by its own legal concept, should not be ruled out.