Editor’s Note: A different entry under the title ‘Objective Regime’, written in 2010 by Carlos Fernández de Casadevante Romani, appeared as part of the online Max Planck Encyclopedia of Public International Law until the publication of this entry in 2023. This new entry has been published at the same web address (URL) as the original entry. The original entry was also published in the 2012 print edition of the Encyclopedia (R Wolfrum (ed) The Max Planck Encyclopedia of Public International Law (OUP Oxford 2012) vol VII, 912–15).

A.  Notion

1  In principle, a treaty is only binding on States parties to it, in accordance with the maxim pacta tertiis (nec nocent nec prosunt). It has been argued, however, that some treaties create ‘objective regimes’, which generate effects erga omnes (Obligations erga omnes). This means that they establish rights and obligations also for States non-parties, often without such States having the option to formally accede to the treaty. Objective regimes would constitute an exception to the pacta tertiis principle.

2  Treaties that are considered as establishing objective regimes typically have a territorial dimension, such as peace treaties, treaties providing for the neutralization or demilitarization of a State or territory, treaties delimiting boundaries, or treaties establishing a regime for international waterways (such as canals or rivers [International Watercourses]). Treaties establishing objective regimes could arguably overcome the tyranny of State consent in contemporary international law, and fill the gaps left by the limited law-making activities of international organizations in relation to international community needs (Salerno [2011] 240–41).

3  The notion of objective regimes does not as such feature in the relevant treaties, but is first and foremost a doctrinal construction. The notion is controversial, as it overrides the hallowed principle that a treaty ‘does not create either obligations or rights for a third State without its consent’, codified in Art. 34 Vienna Convention on the Law of Treaties (‘VCLT’; Vienna Convention on the Law of Treaties [1969]).

4  While the VCLT features a section on treaties and third States (Arts 34–38 VCLT; Treaties, Third-Party Effect), it subjects the creation of treaty obligations or rights for third States to the latter’s consent. As to obligations, Art. 35 VCLT requires the third State’s express acceptance in writing, while as to rights, Art. 36 requires the third State’s assent, although ‘assent shall be presumed so long as the contrary is not indicated’. Finally, Art. 38 notes that a rule set forth in a treaty can become binding upon a third State as a customary rule of international law, a process that also requires the third State’s consent to be bound (Customary International Law). In contrast, objective regimes, at least in some doctrinal iterations, would allow treaties to be ‘objectively’ binding on third States without consent being required.

B.  Discussions in the ILC

5  The notion of objective regime was discussed by two Special Rapporteurs of the International Law Commission (ILC) in its work on the law of treaties, which culminated in the adoption of the VCLT. The notion was eventually discarded, however, at least in the context of VCLT codification.

6  In 1960, Special Rapporteur Fitzmaurice proposed a draft Art. 18, pursuant to which in respect of peace treaties, treaties on neutralization or demilitarization, and treaties of a dispositive (in rem or territorial) character, ‘all States are under a duty to recognize and respect situations of law or of fact established by lawful and valid treaties tending by their nature to have effects erga omnes’ (UN ILC Special Rapporteur G Fitzmaurice ‘Fifth Report on the Law of Treaties’ [1960] 80). Fitzmaurice’s proposal was not discussed by the ILC, however.

7  In 1964, Fitzmaurice’s successor, Special Rapporteur Waldock, proposed to the ILC draft Art. 63 para. 1, pursuant to which ‘[a] treaty establishes an objective régime when it appears from its terms and from the circumstances of its conclusion that the intention of the parties is to create in the general interest general obligations and rights relating to a particular region, State, territory, locality, river, waterway, or to a particular area of sea, sea-bed, or air-space; provided that the parties include among their number any State having territorial competence with reference to the subject-matter of the treaty, or that any such State has consented to the provision in question’ (UN ILC Special Rapporteur H Waldock ‘Third Report on the Law of Treaties’ [1964] 26). Interestingly, Waldock attempted to reconcile his concept of objective regime with the pacta tertiis principle, where he allowed third States to object to the creation of such a regime. Indeed, draft Art. 63, para. 2, provided that ‘(a) A State not a party to the treaty, which expressly or impliedly consents to the creation or to the application of an objective régime, shall be considered to have accepted it’ and ‘(b) A State not a party to the treaty, which does not protest against or otherwise manifest its opposition to the régime within a period of X years of the registration of the treaty with the Secretary-General of the United Nations, shall be considered to have impliedly accepted the régime’ (UN ILC Special Rapporteur H Waldock ‘Third Report on the Law of Treaties’ [1964] 26–27).

8  The majority of ILC members rejected Waldock’s proposal. They were mainly concerned over imperial overreach by the Great Powers, which, under the doctrine, might have the power to impose their will on lesser States (Superpowers and Great Powers). Most notably, ILC member Jiménez de Aréchaga stated that, on the basis of the doctrine, ‘certain groups of States might acquire a sort of legislative power over the rest of the world’, which ‘would be exercised mainly by the Great Powers’ (UN ILC ‘Law of Treaties’ [1964] 101). Jiménez de Aréchaga also decried the heavy burden which would be imposed on States, especially developing States, ‘to review every treaty entered into by other States and to place on record their disapproval of any treaty they thought might fall within the category described in [Art 63] paragraph 1’ (UN ILC ‘Law of Treaties’ [1964] 101) (Developing Countries). For the ILC majority, ultimately, any third-party effects of treaties were to be explained by reference to (what would become) Arts 34–38 VCLT.

9  While the doctrine of objective regimes was set aside for the purpose of incorporation in the VCLT, the doctrine appears to have been relied on in the Vienna Convention on the Succession of States in Respect of Treaties (1978) (State Succession in Treaties). Articles 11 and 12 of this Convention—which has been ratified by only 23 States Parties—provide, inter alia, that a succession of States does not as such affect boundaries or obligations relating to the use of territory established by a treaty. This means that successor States cannot call into question the territorial regimes established by this treaty. The ILC Commentary to these articles explicitly characterizes such a treaty as establishing an objective regime (UN ILC ‘Draft Articles on Succession of States in respect of Treaties’ [1974] 204). Also the VCLT, for that matter, has given treaties establishing a boundary a certain ‘objective’, or at least in rem, status, insofar as Art. 62 (2) (a) provides that ‘[a] fundamental change of circumstances may not be invoked as a ground for terminating or withdrawing from a treaty … if the treaty establishes a boundary’. It is of note that the UN Human Rights Committee takes the view that State succession also does not affect the protection offered by the International Covenant on Civil and Political Rights (1966), stating that ‘once the people are accorded the protection of the rights under the Covenant, such protection devolves with territory and continues to belong to them, notwithstanding change in government of the State party, including dismemberment in more than one State or State succession or any subsequent action of the State party designed to divest them of the rights guaranteed by the Covenant’ (UN HRC ‘General Comment No 26’ para. 4). Accordingly, the Committee considers the Covenant to establish an objective regime, at least for the purpose of State succession. In the literature, this reasoning has been extended to all human rights treaties (Kamminga [1996]).

C.  Practice

10  The doctrine of objective regime was developed against a background of the major European powers imposing territorial settlements in the aftermath of international crises. Most notably, in 1815, at the Congress of Vienna, England, Russia, Austria, and Prussia redrew the post-Napoleonic European political landscape by creating the German Confederation, neutralizing Switzerland, and extending the territory of the Netherlands to Belgium (‘Final Act [General Treaty] of the Congress of Vienna’; Vienna Congress [1815]). To the extent that the lesser powers were present at the Vienna Congress, they simply had to accept the decision of the major powers.

11  Throughout the 19th century, the major European powers, known as the Concert of Europe, also imposed permanent neutrality on Belgium and Luxembourg (1839), neutralized the Congo Basin (General Act of the Conference of Berlin respecting the Congo [1885]), and created free navigation in the Suez Canal (Convention respecting the Free Navigation of the Suez Maritime Canal [‘Convention of Constantinople’] [1888]). These settlements were considered as binding on all States and thus had erga omnes effects, arguably in the interest of international stability and peace.

12  It has been claimed that also international practice of the second half of the 20th century points to the existence of objective regimes. Examples that are typically cited (eg, Subedi [1994] 174–85) are the neutralizations of Laos and Cambodia (1962, 1992), the internationalization of the Panama Canal (Panama Canal Treaty [1977]; Neutrality Treaty [1977]), territorial settlements under UN Security Council resolutions, eg, regarding Iraq (UNSC Res 687 [1991]; UNSC Res 833 [1993]), the demilitarization of Antarctica (Arts IV and X Antarctic Treaty [1959]; see on the latter treaty also Simma [1986]), the Protocol on Environmental Protection to the Antarctic Treaty (1991), and treaties providing for nuclear weapon-free zones (eg, the 1967 Treaty for the Prohibition of Nuclear Weapons in Latin America [‘Treaty of Tlatelolco’]).

13  Furthermore, the 1967 Outer Space Treaty (Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies), the regime for the deep-seabed, the regime for high seas fishing, and a number of environmental protection regimes have been cited as examples of objective regimes creating rights and obligations for third parties, arguably without the latter’s consent being required (Barnes [2000]; Outer Space; International Seabed Area; Fisheries, High Seas).

D.  Judicial Decisions

14  A limited number of decisions of international commissions and tribunals, and opinions or declarations of individual judges, appear to support the notion of objective regime. The most relevant decisions date back to the first half of the 20th century, and pertain to post-conflict international settlements designed by the Great Powers.

15  In 1920, a Committee of Jurists was appointed by the Council of the League of Nations to clarify the status of the Åland Islands, the Permanent Court of International Justice (PCIJ) still being in statu nascendi at the time. Strikingly, the Committee cited ‘the objective nature of the settlement of the Aaland Islands question’ by the Paris Peace Treaty of 30 March 1856, concluded between France Great Britain, Russia, Prussia, Austria, and Turkey, which placed the Aaland Islands under a permanent regime of demilitarization (Report of the International Committee of Jurists [1920] 16). The Committee recalled that the Great Powers of Europe ‘have, on many occasions since 1815, and especially at the conclusion of peace treaties, tried to create true objective law, a real political status the effects of which are felt outside the immediate circle of contracting parties’ (Report of the International Committee of Jurists [1920] 18). According to the Committee, the Aaland Islands settlement was ‘[l]aid down in European interests’, and ‘any State in possession of the Islands must conform to the obligations binding upon it’, regardless of whether it is a party to the 1856 Treaty (Report of the International Committee of Jurists [1920] 18).

16  In 1923, the PCIJ, in the Wimbledon case, appeared to consider the regime governing the Kiel Canal, which links the North Sea to the Baltic Sea, to be an objective regime (Wimbledon, The). Article 380 of the 1919 Treaty of Versailles, the peace treaty which ended the state of war between Germany and the Allied Powers, stipulated that ‘[t]he Kiel Canal and its approaches shall be maintained free and open to the vessels of commerce and of war of all nations at peace with Germany on terms of entire equality’. The PCIJ interpreted this provision as ‘facilitat[ing] access to the Baltic by establishing an international régime, and consequently to keep the canal open at all times to foreign vessels of every kind’, per the intention of the authors of the treaty (Wimbledon 23). Thus, the Versailles Treaty was considered to create obligations erga omnes.

17  In 1950, the International Court of Justice (ICJ) obliquely referred to the doctrine of objective regimes in its advisory opinion on the International Status of South-West Africa. It ruled that the mandate held by South Africa over South West Africa ‘was created, in the interest of the inhabitants of the territory, and of humanity in general, as an international institution with an international object—a sacred trust of civilization’ (International Status of South-West Africa [Advisory Opinion] 132). Accordingly, its status was not affected by the dissolution of the League of Nations under whose auspices the mandate system was established (Mandates). While the continuation of the mandate over South West Africa could possibly be explained by the doctrine of succession, Judge McNair, in his separate (concurring) opinion, was more explicitly of the view that the mandate system was an international regime ‘extending beyond the limits of the actual contracting parties, and giving it an objective existence’ ([Separate Opinion of Judge McNair] [1950] ICJ Rep 146, at 153). As will be explained below, McNair was also one of the main scholarly proponents of the doctrine of objective regime.

18  A year earlier, in 1949, the ICJ, in the context of the international legal personality of the United Nations (UN), famously held in the Reparation for Injuries Suffered in the Service of the United Nations (Advisory Opinion) that ‘fifty States, representing the vast majority of the members of the international community, had the power, in conformity with international law, to bring into being an entity possessing objective international personality, and not merely personality recognized by them alone, together with capacity to bring international claims’ (at 185 [emphasis added]). While this opinion does not pertain to international territorial settlements or regimes, it does recognize that a limited number of States could establish a new entity with erga omnes effects. In the case, this meant that Israel, a third State, was under an obligation to recognize the international legal personality of the United Nations, and its right to demand reparations from Israel in relation to injuries suffered by a UN representative.

19  Finally, a reference to objective international law, even if not to objective regimes proper, can be found in a declaration by Judge Bedjaoui attached to the ICJ’s 1996 advisory opinion on the Legality of the Threat or Use of Nuclear Weapons (Nuclear Weapons Advisory Opinions). In this declaration, he stated, in relation to concepts such as obligations erga omnes, rules of ius cogens, or the common heritage of mankind that ‘[t]he resolutely positivist, voluntarist approach of international law still current at the beginning of the century … has been replaced by an objective conception of international law, a law more readily seeking to reflect a collective juridical conscience and respond to the social necessities of States organized as a community’ ([Declaration of President Bedjaoui] [1996] ICJ Rep 268 para. 13 [emphasis added]).

E.  Scholarship

20  None of the treaties discussed above refers explicitly to the notion of objective regime. In essence, the notion is a creation of legal doctrine, which endeavors to systematize relevant practice. Only few writers have addressed objective regimes in detail.

21  McNair was arguably the first writer to coin and elaborate on the notion of objective regime. He did so in a number of successive publications. In 1925, McNair wrote that the pacta tertiis maxim has certain qualifications, and that there are treaties which ‘have a law-creating effect beyond the immediate parties’, citing in particular the 1815 treaties of the Vienna Congress, the 1856 Treaty of Paris, the peace treaties concluding the First World War, and treaties regarding navigational rights (McNair [1925] 122). In 1930, he considered that such treaties ‘settle the political affairs of a group of countries in a particularly solemn and semi-dictatorial fashion which likens the arrangement to a governmental act imposed from above upon the parties affected, rather than to a voluntary bargain between them’ (McNair [1930] 112). In 1961, McNair linked this quasi-legislative role of particular States to the doctrine of erga omnes effects, arguing that certain kinds of treaties have erga omnes effects based on ‘some inherent and distinctive juridical element in those treaties’, in particular the decision of a group of States to grant real rights or rights in rem (eg, a boundary treaty or a treaty of cession), or act in the public interest in relation to a situation with a certain permanence (McNair [1961] 255).

22  McNair’s ideas subsequently influenced ILC Special Rapporteur Waldock’s 1964 attempt to devote a VCLT article to objective regimes (see above). Waldock’s failure to convince the ILC did not put the issue doctrinally to rest. Most notably, in 1980, Klein, writing in German, produced the first book-length treatment of the subject (Statusverträge im Völkerrecht: Rechtsfragen territorialer Sonderregime, with a summary in English at the end of the book). Klein characterized treaties establishing objective territorial regimes as ‘status treaties’ (Statusverträge), provided that they are concerned with a land or maritime territory, that the intention of the parties is to establish a regime in the interest of the international community and to create a regime which is valid for third parties, and that at least one of the parties has a territorial competence with reference to the subject-matter of the treaty (Klein [1980] 351–53). According to Klein, the masters of the treaty can settle the matter erga omnes under the following condition: ‘From the assertion made by the contracting parties to serve the general interest and from the participation of the power which has territorial competence for the settlement, there results such a strong legal claim that the attribution of the asserted competence must be admitted by those States which have not objected to this claim’ (Klein [1980] 356). What is striking is that Klein attached legal consequences to the masters of the treaty’s mere assertion to serve the general interest, although he compensated this statement by explicitly allowing third States to resist the erga omnes effect of the objective regime thus created.

23  In 1996, Ghanbari Jahromi carried out, for the first time, a book-length English-language study of objective treaty regimes. Ghanbari Jahromi argued that the doctrine of objective regimes is not lex lata, as it is hardly supported by State practice. He added that it should not be lex ferenda either, as it negates the pacta tertiis and res inter alios acta principles that are central to the contemporary theory of international law (Ghanbari Jahromi [1996] 354–59). He observed that most of the claimed erga omnes effects of objective regime can in fact be explained by the consent-based rules on the effects of treaties on third States stipulated in the VCLT, including the possibility that the regime has become binding on the basis of customary international law (Arts 34–38; Ghanbari Jahromi [1996] 359). Ghanbari Jahromi’s analysis of the doctrine and practice of objective regimes is most cogent. Unfortunately, perhaps because his study was not published commercially, it has not had a major impact on the field (yet).

24  A critical stance toward the existence of objective regimes is also taken by M Fitzmaurice in her wide-ranging study on ‘Third Parties and the Law of Treaties’ (2002). Fitzmaurice observed that fundamental legal questions as to the very existence and legal nature of objective regimes remain unresolved (Fitzmaurice [2002] 82), and that ‘there is no theory in international law that really justifies the existence of such régimes in a fully convincing manner’ (Fitzmaurice [2002] 136). Analysing the practice and judicial decisions that are typically cited as supportive of the existence of objective regimes, she argued that any perceived third-party effects of the relevant regimes in fact flow from Arts 34–38 VCLT, whereas other regimes may only have granted benefits but not rights (eg, the Panama Canal Treaty), while the binding force erga omnes of yet other regimes (eg, the Antarctic Treaty) may have been negated by certain States (ibid 84–136).

25  Salerno, writing in 2011, was equally critical of the capacity of parties to a treaty establishing an objective regime to compel third States to respect the treaty’s provisions, but nevertheless took the view that ‘third states must take into consideration the reasons that led the states parties to establish such a regime’ (Salerno [2011] 242). He based this approach on the abuse of rights doctrine, meaning that third States are barred from fully exercising their freedom in case the treaty establishing the objective regime is closely connected to ‘generally recognized principles’ (Salerno [2011] 242). To a certain extent, this echoes ILC Special Rapporteur Fitzmaurice’s draft Art. 18, pursuant to which, regarding a number of treaties (establishing objective regimes), ‘all States are under a duty to recognize and respect situations of law or fact established by lawful and valid treaties tending by their nature to have effects erga omnes’ (UN ILC Special Rapporteur G Fitzmaurice ‘Fifth Report on the Law of Treaties’ [1960] 80). Under such an approach, objective treaties can at most create indirect effects, although it is not exactly clear what this would mean in practice.

26  Lately, the doctrine of objective regime has mainly caught the attention of international environmental lawyers, who consider the erga omnes effects of the doctrine to be particularly useful to more comprehensively address global environmental threats. Thus, Barnes observed that a number of environmental regimes, notably regarding marine pollution, driftnet fishing, and ozone depletion, ‘manifest objective characteristics’, and believed that ‘objective environmental regulation will continue to develop’ (Barnes [2000] 130)—while nevertheless admitting that objective regimes may not yet have crystallized as lex lata (Barnes [2000] 145). Rayfuse (2000) and Fitzmaurice (2002), in contrast, took the view that this may be wishful thinking given the lack of State practice to the effect that such treaties bind third parties.

27  From a doctrinal perspective, global environmental treaties do not fit well with the original conception of objective regimes, insofar as such treaties may not include among their number any State having a particular territorial competence over the subject-matter, and are not meant to ‘settle’ a situation after a period of military or political upheaval. In 2021, Soares de Oliveira argued, however, that for ‘some objective environmental legal situations, the element of territorial competence … can be supplemented by an ad hoc emergency environmental competence’, which would ensure the erga omnes validity of the objective environmental regime (Soares de Oliveira [2021] 68).

28  Also outside the field of international environmental law, the doctrine of objective regime is occasionally invoked by contemporary writers to conceive of the erga omnes effects of specific treaties. For instance, certain objective effects vis-à-vis non-parties have been ascribed to the UN Charter, especially the provisions relating to dispute-resolution by the UN Security Council (Chinkin [1993] 108). Pergantis (2020), for his part, applied the doctrine to the Final Agreement between Greece and henceforth North Macedonia of 17 June 2018 (‘Prespa Agreement’), which explicitly provides that the parties shall use the official name ‘Republic of North Macedonia’ erga omnes (Art. 1 Prespa Agreement; North Macedonia). While he concluded that the contracting parties may have lacked the relevant intent to create an objective regime (Pergantis [2020] 83), he argued, moving forward, that such an intent may possibly be derived from the parties’ subsequent practice, as well as that third States may tacitly agree to the regime (Pergantis [2020] 84–85; Tacit Agreements).

F.  Assessment

29  Noteworthy scholarly efforts have been made to theorize a purported practice of objective treaty regimes creating erga omnes effects vis-à-vis third States. Still, the doctrine remains somewhat obscure and controversial. Also the relevant practice is, on closer inspection, far from conclusive.

30  The doctrine may have existed in an era of Great European Powers imposing settlements by dint of treaty regimes, which contained quasi-legislation creating rights and obligations for lesser powers not party to the treaty regime without the latter’s consent being required. This ‘public law’ conception of objective regime has become obsolete, however. Imperial imposition of law is no longer in keeping with basic tenets of contemporary international law, in particular sovereign equality and the requirement of State consent to be bound (States, Sovereign Equality).

31  This explains why 20th century legal scholars, such as Waldock and Klein, have mitigated the public law conception of objective regime by requiring, one way or the other, express, implied, or presumed consent, non-objection, or acquiescence, as a condition for third parties to be bound by an objective treaty regime. If third-party assent is required for the regime to become binding, however, it is no longer objective. The third-party effects of the regime may then be explained by other doctrines, in particular the existing VCLT regime for third-party effects (Arts 34–38), and customary international law. For instance, in 2019, the Appeals Chamber of the International Criminal Court (ICC) ruled, in relation to the prosecution and arrest of Omar Al Bashir, the head of State of Sudan, a State non-party to the Rome Statute (the treaty establishing the ICC), that Art. 27 (2) Rome Statute, which considers official capacity to be irrelevant before the ICC, ‘reflects the status of customary international law’ (Prosecutor v Omar Hassan Ahmad Al-Bashir [Judgment in the Jordan Referral re Al-Bashir Appeal] [2019] para. 103) and that ‘there is neither State practice nor opinio juris that would support the existence of Head of State immunity under customary international law vis-à-vis an international court’ (para. 113). The Appeals Chamber did not consider the parties to the Rome Statute to have established an objective regime that ipso facto created third party effects.

32  The doctrine of objective regime may nevertheless be attractive to overcome contemporary global governance challenges, especially in the environmental field, but perhaps also in the human rights field. International human rights and environmental treaties may then ipso facto create binding legal regimes, even for States non-parties to the treaties. It remains the case, however, that the doctrine is poorly compatible with the current decentralized international legal system and the principle of consent.

33  Concluding, the doctrine of objective treaty regimes has little theoretical and practical purchase in contemporary international law, given the predominance of the pacta tertiis principle. Obviously, this has not stopped the major powers from imposing their legal will on less powerful States by means of various hegemonic legal practices. They may do so by coaxing the latter into joining treaties, but also by enacting non-consent-based unilateral regulation ‘in the international interest’.