2.1 Introduction
The rules of interpretation in international law are closely associated with the Vienna Convention on the Law of Treaties (VCLT), particularly Articles 31, 32 and 33 of the Convention.Footnote 1 The VCLT context creates an impression that interpretation is a concept peculiar to international treaties, that is, written sources of international law with a textual basis and drafting history.Footnote 2 However, the work of Panos Merkouris demonstrates that the rules of interpretation also operate beyond treaty law.Footnote 3 Although customary international law and general principles of law are mainly unwritten sources, this does not mean that they are not subjected to any rules of interpretation and that they do not have a role in the interpretation techniques.Footnote 4 Obligations erga omnes and jus cogens norms pose an additional challenge to the interpretation techniques. It is not entirely settled where these concepts are derived from and what their relationship is with the formal sources of international law, as reflected in Article 38(1) of the Statute of the International Court of Justice (ICJ).Footnote 5
Some scholars have called general principles systemic elements of international law that determine the scope and applicability of the rules stemming from treaties and custom,Footnote 6 while the origins of contemporary jus cogens are derived from the idea of jus strictum and zwingendes Völkerrecht (‘compelling law’ as opposed to ‘voluntary law’).Footnote 7 The idea of jus cogens thus also presupposes the existence of a systemic structure in international law.Footnote 8 The systemic rule of general principles and jus cogens are closely linked to the VCLT rules on interpretation and, in particular, to the interpretation technique known as systemic integration.Footnote 9 As Lekkas and Merkouris demonstrate, general principles of law indeed played a very central role in the drafting history of Article 31(3)(c) VCLT.Footnote 10 Indeed, in his seminal work on the law of treaties, Arnold McNair argued that treaties need to be ‘applied and interpreted against the background of the general principles of international law’;Footnote 11 and Campbell McLachlan has noted:
A treaty will normally be capable of interpretation and application according to its own terms and context. But in hard cases, it may be necessary to invoke an express justification for looking outside the four corners of a particular treaty to its place in a broader framework of international law, applying general principles of international law.Footnote 12
This chapter is concerned with the role of the general principles of law, obligations erga omnes and jus cogens norms in the rules of interpretation of the sources of international law. In particular, the chapter considers the function of general principles, obligations erga omesand jus cogens in the interpretative method commonly known as systemic integration of international law. This method is most notably reflected in Article 31(3)(c) VCLTFootnote 13 but also has a life outside of the VCLT and outside of treaty law in general. The chapter argues that the interpretation techniques of the VCLT in general, and Article 31 of the Convention in particular, presume a systemic structure of international law. This systemic structure is underpinned by certain public law concepts, which operationalize the otherwise inherently private law nature of international treaty and customary law.
The private law paradigm in principle makes international law a network of bilateral obligations between states. However, as James Crawford noted, ‘at least some obligations are universal in scope, and cannot be reduced to bundles of bilateral interstate relations’.Footnote 14 It is argued in this chapter that general principles of law, obligations erga omnes and jus cogens norms provide for at least a rudimentary public law framework, which enables an application and systematization of treaty and customary law. Such an application and systematization takes places through the process of interpretation.
This chapter does not primarily deal with the interpretation techniques pertaining to customary international law. With respect to custom, this chapter largely subscribes to the position taken in the previous work of Merkouris in the framework of the TRICI-Law project.Footnote 15 This chapter rather explores related concepts, as the line between custom, general principles, obligation erga omnes and jus cogens norms indeed remains fuzzy. To illustrate, it has been argued that jus cogens may be both: customary international law and a general principle of law.Footnote 16 The concept of customary international law therefore remains important for this contribution, but the chapter does not delve into the theoretical underpinnings of custom and its interpretation techniques.
The chapter outlines the idea of an international legal system and argues how the inherently private law system of public international law had to borrow certain public law principles in order to be able to function as a system. Subsequently, the chapter considers the vertical relationship between the international community and its subjects. In so doing, the chapter seeks to demonstrate how such vertical elements created a systemic legal structure.
2.2 Outlining an International Legal System
In the Oil Platforms case, the ICJ reasoned:
[U]nder the general rules of treaty interpretation, as reflected in the 1969 Vienna Convention on the Law of Treaties, interpretation must take into account ‘any relevant rules of international law applicable in the relations between the parties’ (Art. 31, para. 3 (c)). The Court cannot accept that Article XX, paragraph 1 (d), of the 1955 Treaty [of Amity between the United States and Iran] was intended to operate wholly independently of the relevant rules of international law on the use of force, so as to be capable of being successfully invoked, even in the limited context of a claim for breach of the Treaty, in relation to an unlawful use of force. The application of the relevant rules of international law relating to this question thus forms an integral part of the task of interpretation entrusted to the Court.Footnote 17
In Oil Platforms, the ICJ operationalized Article 31(3)(c) VCLT and the systemic nature of international law. The provisions of international treaties should not be read in a legal vacuum – they ought to be interpreted with other rules of international law in mind. In this sense, the ICJ had previously established in Right of Passage that treaties ought to be ‘interpreted as producing and as intended to produce effects in accordance with existing law and not in violation of it’Footnote 18 and in the Namibia Advisory Opinion that ‘an international instrument has to be applied within the framework of the entire legal system prevailing at the time of the interpretation’.Footnote 19 This section seeks to outline the systemic nature of international law and the importance of systemic integration. In so doing, the section situates the VCLT rules on treaty interpretation within the broader theoretical debate on the fragmentation and systemic coherence of international law.
2.2.1 The Systemic Nature of Interpretation
From the doctrinal standpoint, the interpretation of the sources of international law usually begins with the rule on treaty interpretation codified in Article 31 of the VCLT.Footnote 20 This provision provides that international treaties shall be interpreted in good faith and in accordance with the ordinary meaning of the terms used in the treaty.Footnote 21 At the same time, the object and purpose of the treaty are also relevant, and the preamble and possible annexes ought to be taken into account.Footnote 22 Furthermore, Article 31 provides that any subsequent treaties between the parties, the practice developed later in the interpretation of relevant obligations and any other rules of international law that bind the treaty parties shall be taken into account.Footnote 23 Moreover, as McLachlan argues, the Article 31(3)(c) formulation ‘refers to rules of international law in general. The words are apt to include all of the sources of international law, including custom, general principles, and, where applicable, other treaties.’Footnote 24
The provisions of Article 31 appear to be logical: it is necessary to start with the underlying text; the words used in this text should not be attributed any unusual meanings; the treaty provisions should be contextualized within the treaty as a whole, while somehow maintaining a balance between the intentions of the treaty parties at the time of the conclusion of the treaty and the subsequent practice. This is where a problem can arise: how to correctly determine the balance between the intention of the treaty parties at the time of the conclusion of the treaty and contemporary practice.
There seems to be no general rule regulating this, and the balance depends on the particular treaty in question. The European Convention on Human Rights (ECHR) is interpreted as a ‘living instrument’ whereby the intentions of the original parties seven decades ago no longer play any role,Footnote 25 while the Charter of the United Nations (UN) is largely still interpreted in accordance with the intentions of the parties at the end of the Second World War.Footnote 26 At the same time, it should be noted that Article 32 VCLT provides that the travaux préparatoires shall also be considered. With respect to some treaties, for example, the UN Charter, this is regularly done decades after their conclusion, while in others, the practice can quickly outgrow the framework of the original text and thus the travaux quite soon become largely irrelevant.
It clearly follows from Article 31 VCLT that no international treaty is an isolated system of rules. When interpreting treaty provisions, it is necessary to take into account the other international obligations of the treaty parties and other relevant rules of international law. In other words, one should not put a treaty or its individual provisions at the top of the hierarchy and subordinate to it either other treaties or other sources of international law, such as customary international law and general principles of law. The rules of interpretation under Article 31 require a systemic integration of the rules of international law, regardless of the source from which such rules may be stemming.Footnote 27
To illustrate, sometimes the question arises of whether international human rights law even applies in armed conflict.Footnote 28 The preferred view nowadays appears to be that human rights law still applies in armed conflict; it only needs to be systematically integrated with the rules of international humanitarian law.Footnote 29 The scope of the relevant rules of human rights law can thus change, mostly becoming narrower, but this does not create a hierarchy or superiority of one treaty regime over another.
It is worth emphasizing that for systemic integration in the sense of Article 31(1)(c) VCLT, treaty interpreters are needed who (still) operate within the system of international law, that is, the interpreters who have not already placed themselves outside the system or see themselves in it with only one foot. An example of such an interpreter would be the Court of Justice of the European Union,Footnote 30 but to a lesser extent also the panels in the framework of the World Trade Organization (WTO).Footnote 31 When the interpreter no longer sees itself in the system of international law, this leads to fragmentation and so-called self-contained regimes and hierarchical placement of one treaty regime above the rest of international law. As noted by the Study Group of the International Law Commission (ILC) in the Fragmentation Report, there is a need
to carry out interpretation such that the rules are seen in the light of some comprehensible and coherent objective, so as to prioritize concerns that are more important at the cost of less important objectives. This is all that article 31, paragraph 3 (c), requires: the integration into the process of legal reasoning – including reasoning by courts and tribunals – of a sense of coherence and meaningfulness. Success or failure here is measured by how the legal world views the outcome.Footnote 32
However, as Adamantia Rachovitsa cautions:
the principle of systemic integration – either allegedly derived from Article 31 (3)(c) VCLT or as a stand-alone principle – cannot remedy the international courts’ fragmented lens. The purpose of interpretation is not to integrate treaties into a coherent whole, but to introduce into the process of interpreting a treaty any relevant rules and to offer interpretive guidance (Article 31(3)(c) VCLT being one tool for accomplishing this).Footnote 33
Indeed, systemic integration is no panacea. It is not a solution that would harmonize international law or even constitutionalize it. Nevertheless, systemic integration can provide for certain conceptual solutions and rudimentary public law tools for the interpretation of private law type of legal obligations. While a number of doctrinal writings have assumed that a system can only function if it is constitutionalized or otherwise hierarchical in nature,Footnote 34 McLachlan explains that ‘the importance of the rules of customary international law and general principles of law … [in the systemic integration process] is not in their overriding character’.Footnote 35 Indeed, systemic integration is not about hierarchy and overriding, it is about reconciling two or more obligations and shaping their scopes by reading one into another.
2.2.2 From Fragmentation to Systemic Coherence
In his seminal work The Concept of Law, H. L. A. Hart argued that international law was a simple set of primary rules without any systemic coherence significant for municipal legal orders.Footnote 36 The Report of the Study Group of the ILC on Fragmentation of International Law came to a similar conclusion: ‘The international legal system has never enjoyed the kind of coherence that may have characterized the legal orders of States.’Footnote 37
The lack of systemic coherence can lead to problems in the practical application of the rules of international law. As the Study Group of the ILC further observed:
[T]he emergence of conflicting rules and overlapping legal regimes will undoubtedly create problems of coordination at the international level. But … no homogenous, hierarchical meta-system is realistically available to do away with such problems. International law will need to operate within an area where the demands of coherence and reasonable pluralism will point in different directions.Footnote 38
International legal scholarship has tried to overcome the lack of systemic coherence by introducing certain concepts and principles from municipal legal systems. The project on international constitutionalism has been particularly prominent in this regard. Its proponents have indeed tried to conceptualize international law as a constitutionalized ‘homogenous, hierarchical meta-system.’Footnote 39 But critics have pointed out that any instances of a hierarchy of norms in international law are merely perceived, while the practical application of legal norms remains non-hierarchical in nature.Footnote 40 This line of thought originates in the Hartian description of international law as a non-system, and then seeks to achieve at least some systemic coherence through the development of the so-called conflict rules.Footnote 41 These are the rules that resolve conflicts between different norms and sub-regimes of the international legal order. This chapter challenges the assumption that no homogenous meta-system is available to ensure a systemic coherence of the international legal order. But such a meta-system does not need to be hierarchical in nature, and the overarching systemic framework does not need to be constitutionalism or constitutional theory.
International law is a legal system derived from states. This is not to say that actors other than states do not exist in this system. But states are the actors that have the full international legal capacity. This also follows from the formal sources of law: it is states that conclude international treaties in the sense of the VCLT;Footnote 42 and it is state practice, combined with opinio juris (again derived from states) that forms customary international law.Footnote 43 From a purely international perspective, international law as law between states operates in a horizontal paradigm. However, the inter-state legal obligations are only one level of international legal regulation.
International law-making is reminiscent of the concept of creation of legal obligations in municipal private law. For example, international treaty obligations are conceptually similar to contractual obligations domestically. Indeed, some languages do not even employ separate terms for contracts and treaties, and it is understood that treaties are in their essence contracts between states. Some treaties even use the term high contracting parties. Despite these private law foundations of international law, certain public law concepts have nevertheless been introduced into the international legal order. Yet it remains ever-elusive how these concepts operate. In the Barcelona Traction case, the ICJ pronounced that certain obligations are ‘the concern of all States. In view of the importance of the rights involved, all States can be held to have a legal interest in their protection; they are obligations erga omnes’.Footnote 44 Following this logic, when certain norms are breached, it is not a single state but the international community as a whole who is injured. This is well-illustrated also in the position of the Study Group of the ILC on Fragmentation of International Law: ‘If a State is responsible for torturing its own citizens, no single State suffers any direct harm … such action violates some values or interests of all, or … [of] the international community as a whole.’Footnote 45
Indeed, as Sarah Thin has explained:
The international community interest is at the centre of this global community structure. It both complements and strengthens it. Secondary rules protecting the community interest as such, like those relating to obligations erga omnes and jus cogens, integrate certain substantive shared values and common interests within this overarching legal structure. Furthermore, some of the foundational principles or aims that underlie this legal order – the principle of legality, the rule of law – can be seen as part of the international community interest. None of these community interest norms would be possible without the recognition that there are some rules which extend beyond basic bilateral structures. The notion that there can exist forms of legal responsibility that engage the interest of the community as a whole, rather than merely an injured state, are fundamental to the existence and recognition of that community itself.Footnote 46
At least theoretically, international legal doctrine has thus established a distinction between horizontal bilateral legal relations between states and vertical legal relations between the state and the international community. This is similar to the methodological divide between private law and public law known in municipal legal systems. Private law governs the horizontal legal relations between different persons of law (contract and torts),Footnote 47 while public law regulates vertical relations between the community (the state) and the subjects of law, as well as the relations between the organs of this public community (constitutional law, administrative law, criminal law).Footnote 48
In international law, the distinction between private and public international law means something quite different. Public international law has traditionally developed as a system of rules governing obligations between states, which are for the most part reminiscent of contracts and torts domestically. Private international law has developed as a system of rules governing the relationship between the individual and foreign law/foreign states (e.g. marriage concluded by nationals of different states). The divide between public and private international law is therefore conceptualized on the basis of the identity and nature of actors in a municipal legal system. To put it simply, where the rules govern relations between states, they are called public and where they regulate relations between individuals (e.g. application of foreign law), they are called private.
A theoretical divide between private law and public law akin to the one known in municipal legal systems also exists within the normative framework of the international legal order. In other words, the public/private law divide exists even within the set of rules traditionally – and somewhat misleadingly – termed as public international law. Yet this divide has not been thoroughly constructed in international legal theory. This is where the chapter turns next. It will be argued that international law functions as a system precisely because the private law type of obligations stemming from international treaties and custom are interpreted in line with certain systemic elements that provide for a rudimentary public law umbrella in the system of international law.
2.3 The Relationship between the ‘International Community’ and Its Subjects
Thus far, it has been established that public international law operates within a private law paradigm. States make treaties and states can breach those treaties. An individual state can only breach a treaty to which it is a party. We are essentially operating within a contractual logic. Meanwhile, multilateral treaties, the concept of customary international law and some other concepts, such as jus cogens and obligations erga omnes, have introduced certain elements of public law or at least certain elements of public law reasoning within this private law paradigm. This section considers where the limits of the public law paradigm are in public international law, where the international legal system operates beyond the strict contractual logic and how interpretation and systemic integration indeed operationalize the contractual logic of international treaties.
2.3.1 Vertical Elements in a Horizontal System
In municipal settings, public law and political theorists have been investigating the relationships between (i) institutions of the state and (ii) the state and the individual. This is necessarily different in international law where the actors involved differ from those at domestic level. Arguably, the relationship between the institutions of the international community have been addressed by the studies on fragmentation of international law.Footnote 49 These studies have addressed the problem of the relationship between the different regimes of international law built around different institutions (e.g. WTO law, international criminal law, international human rights law, international investment law) and have proposed a robust system of conflict rules to regulate the relationship between these regimes.Footnote 50 At the same time, the vertical relationship between the state and the individual has remained either understudied or overtly influenced by municipal theories that are not always readily transposable to the international level.
Inspired by the rise of international human rights law and international criminal law after the Second World War, some scholars have started to place the individual in the centre of the international legal system and have conceptualized a domestic-like vertical relationship between the individual and the international community.Footnote 51 But international human rights and international criminal law are still derived from the law-making powers of states. The scope of these legal regimes depends on whether or not a particular state is a party to a certain treaty, whether it has filed reservations to that treaty and sometimes also on how states have voted in the UN Security Council. A good example is the Rome Statute of the International Criminal Court (ICC). While the court was set up to deal with criminal responsibility of individuals, its jurisdiction depends on the will of states and is governed by certain treaty-law mechanisms (e.g. ratification of the Rome Statue, non-party acceptance of jurisdiction, UN Security Council referral). In other words, the position of the individual in international law is not regulated by a ‘public law of the international community’ but by a private law system of treaty-created obligations between states.
If a ‘public law of the international community’ exists, the vertical relationship in this system is the one between the international community and the state. On the international plane, it is the state that takes the position of the individual in a municipal public order. International human rights and international criminal law may well play an important role in the political theory governing the vertical relationship between the international community and the state, but this is because the protection of human rights and punishing international crimes belong to the fundamental values of the international community as a whole.
International human rights and international criminal law in this public law model do not operate from the level of an individual but from the overarching level of the community vis-à-vis the state. It needs to be asked whether the notion of ‘the international community as a whole’ can be conceptualized as a legal fiction to represent an international sovereign authority and develops a political theory of international law that defines the vertical relationship between the fictitious international sovereign – the international community as a whole – and the state.
2.3.2 The Public Law Concepts in the International Legal Order
The use of phrases such as ‘the international community as a whole’ may be seen as a silent adoption of the idea of public law within the international legal order. Such phrasings introduce a sense of a community, but does this have any implications for how international law operates? The debate seems to have been squeezed between two somewhat difficult concepts: obligations erga omnes and norms of jus cogens.Footnote 52 The norms most commonly associated with these two concepts are the prohibitions of torture, slavery, racial discrimination, aggression, genocide and the right of self-determination (or rather prohibition of colonialism).Footnote 53 Instead of looking for hierarchical – or even constitutional – superiority of these concepts,Footnote 54 international legal theory needs to identify their theoretical foundations and ask what these foundations tell us about the idea of public law that is lingering in the background.
In one explanation, all non-bilateral obligations have an erga omnes character.Footnote 55 This view is problematic as it ignores the ICJ’s reference to the ‘importance of the rights involved’, contained in the Barcelona Traction dictum. The ‘importance’ is a substantive issue and can only be defined by the special character of the obligations at stake. Maurizio Ragazzi argues that the obligations of this character have two components: ‘the moral content’ and the ‘required degree of support by the international community’.Footnote 56 The concept of obligations erga omnes thus reflects the notion of a value-loaded international community interest. However, when establishing importance for the international community as a whole, the ICJ has only given circular references and rather generally invoked norms and principles of international law. In East Timor, the Court accepted the erga omnes character of the right of self-determination by arguing that self-determination was ‘one of the essential principles of contemporary international law’.Footnote 57 East Timor thus defines the ‘importance’ identified in Barcelona Traction as something that is ‘essential’. Such circularities are of little help where one needs to explain which norms are the concern of the ‘international community as a whole’, why that is so, and how is that manifested in the international legal system.
The ICJ has also been unable to identify obligations erga omnes, their content and underpinnings, on the basis of the formal sources of law alone. As Maurizio Ragazzi has put it, obligations erga omnes reflect ‘an exceptionless [sic] moral norm (or moral absolute) prohibiting an act which, in moral terms, is intrinsically evil (malum in se)’.Footnote 58 According to Ragazzi, obligations erga omnes are binding not only because states agree that they are, but even more importantly, ‘because nobody can claim exceptions from moral absolutes’.Footnote 59 The second claim, that ‘moral absolute’ operates as a direct source of international law, remains debatable. It is nevertheless undisputed that the concept of obligations erga omnes has its underpinnings in strong moral values and it is these underpinnings that shape international law-making.
Although the concept of obligations erga omnes is value-loaded, it is not seen as a hierarchically superior international law. The Report of the Study Group of the ILC on Fragmentation of International Law defines the concept along the following lines:
A norm which is creative of obligations erga omnes is owed to the ‘international community as a whole’ and all States – irrespective of their particular interest in the matter – are entitled to invoke State responsibility in case of breach. The erga omnes nature of an obligation, however, indicates no clear superiority of that obligation over other obligations. Although in practice norms recognized as having an erga omnes validity set up undoubtedly important obligations, this importance does not translate into a hierarchical superiority.Footnote 60
Obligations erga omnes may thus be seen as a legal manifestation of certain shared community values in the international community, or of an international public order. While the concept may encompass ‘moral absolutes’, it does not take any hierarchical precedence over other rules of international law. The legal effects of these obligations remain unclear. It thus also remains unclear how these shared community values (the international public order) are accommodated within the international legal system. It does appear that obligations erga omnes and their community interest are conceptual in nature; they reflect a sense of a system and community values that stretch beyond the pure bilateral or contractual logic of international law.
There is a great deal of criticism that, after introducing obligations erga omnes in Barcelona Traction, the ICJ did not develop this concept further and its normative effects thus remain unclear.Footnote 61 Although no specific rule may follow from the concept of erga omnes obligations directly, the concept introduces a systemic way of thinking and creates a vertical relationship between the states and the community. This element of public law influences the interpretation of treaties and custom: the obligations they generate are not necessarily only bilateral in nature, and international law also imposes certain systemic, community-oriented boundaries on the creation and interpretative scope of international legal obligations.
A strong sense of an international community is also inherent in the concept of jus cogens. For a long time, the ICJ had been reluctant to employ the term jus cogens and was referring to an erga omnes character as virtually a synonym for jus cogens.Footnote 62 It is now somewhat difficult to separate the two concepts. The ICJ has not explored the content of obligations erga omnes beyond the overlap with jus cogens, which is itself a somewhat mysterious concept.Footnote 63
It is in the nature of jus cogens norms that they have an erga omnes effect.Footnote 64 Indeed, we are talking about jus cogens norms and erga omnes obligations. Arguably, jus cogens violations trigger erga omnes obligations – for the international community as a whole. Yet not all obligations erga omnes are to be found on the flipside of jus cogens.Footnote 65 Which obligations have an erga omnes but not jus cogens character remains unclear. Christian Tams concludes that ‘[e]rga omnes outside jus cogens is likely to remain uncharted territory until States begin to invoke the concept more commonly in formalised proceedings’.Footnote 66 Obligations erga omnes may be seen as a legal manifestation of the international community interest. To the extent of their overlap with norms of jus cogens, they may also be seen as an enforcement mechanism of the latter. It is wrong, however, to see obligations erga omnes as hierarchically superior law. What implications does this have for the idea of an international public order?
If one state violates the prohibition of aggression by invading another state, there is indeed an injured state, but the exclusivity of the bilateral model fails to reflect inter alia the rights of other states to invoke responsibility. These structures that we have developed around community interest norms and obligations, from erga omnes to jus cogens, break apart the exclusivity of the bilateral model and impose an extra-state interest. As such, this traditional relationship-based model is no longer sufficient to describe the responsibility that arises from such breaches.Footnote 67
Erga omnes obligations and jus cogens norms thus reflect a shift of paradigm from a strictly bilateral private law–like international law to a more systemic and community-oriented model, which adds at least a very basic vertical relationship between states and the international community.
2.3.3 International Community Values and Limitations on Contractual Freedom
In the VCLT, the concept of jus cogens was for the first time unequivocally mentioned in international treaty law.Footnote 68 However, even in this instance it was only given a rather narrow power to void treaties. The Convention also remained silent on the content of the concept. Article 53 of the VCLT, inter alia, provides that ‘a peremptory norm of general international law is a norm accepted and recognized by the international community of States as a whole’.Footnote 69 The concept of peremptory norms thus also rests on the presumption of the existence of an international community of states with a shared interest. It is notable, however, that the VCLT qualified the notion of the international community with states, while the ICJ a year later, with regard to obligations erga omnes, only referred to the international community. The Court known for its restrictive interpretations of international law certainly did not omit ‘states’ accidentally.
In the Article 53 definition, a peremptory norm is subject to acceptance – by the international community of states as a whole – of the normative content as well as its peremptory character. Does this mean that jus cogens is an inherently treaty law concept? The concept indeed predates the 1969 VCLT and was invoked by writers even in the pre–Second World War era.Footnote 70 At the time, it was unclear whether or not it was a concept generally operating in international law. This has now been generally accepted.Footnote 71 Even the VCLT reference to ‘general international law’ suggests that jus cogens is a concept grounded outside of treaty law but is capable of having systemic effects on the conclusion and interpretation of treaties.
Any norm of customary international law requires its acceptance by states through state practice and opinio juris. However, the acceptance of the special peremptory character, not only normative content, by ‘the international community of states as a whole’ points to the strong ethical underpinning of these norms.Footnote 72 Sandesh Sivakumaran argues that jus cogens represents a minimum threshold of the international value system.Footnote 73 The strong community-oriented ethical underpinning of jus cogens norms has implications for law-making. International law is, in principle, a consensus-based legal system. States create treaty obligations for themselves and at free will. It is state practice and opinio juris that leads to the emergence of customary norms of international law, from which states again have an escape route through the concept of a persistent objector. In principle, it is only new states that become automatically bound by pre-existing customary law and even automatically accede to certain treaties previously governing their territory (e.g. human rights treaties).Footnote 74 Yet the peremptory status of certain norms, encompassing the minimum threshold of the international value system, also overrides some fundamental tenets of a consensus-based international law-making.
The ethical underpinning of the peremptory norms can compensate for deficiencies in universal acceptance of these norms. In this context, three examples appear to be particularly instructive: (1) the right to the freedom from torture is supported by very strong opinio juris, yet state practice is rather weak. There is nevertheless little doubt that the freedom from torture has a jus cogens status.Footnote 75 (2) Apartheid South Africa claimed that it was a persistent objector to the prohibition of racial discrimination. This claim was universally rejected on the basis that unlike ordinary customary law, peremptory law does not allow for the persistent objector’s status.Footnote 76 (3) France used to claim that it had never consented to the concept of jus cogens as such.Footnote 77 This argument was rejected and now even France has accepted the binding nature of these norms in terms of both content and character.Footnote 78
These examples reveal that with regard to peremptory norms, international law-making may work differently. As Robert McCorquodale argues, ‘some human rights create legal obligations on a state irrespective of whether it has ratified a particular treaty, either because the human right is part of customary international law and so binding on all states or by virtue of a rule of jus cogens, which no state can derogate from or evade by contrary practice’.Footnote 79 Moreover, in Furundzija, the International Criminal Tribunal for the former Yugoslavia (ICTY) reasoned: ‘Because of the importance of the values [which the prohibition of torture] protects, this principle has evolved into a peremptory norm of jus cogens, that is a norm that enjoys a higher rank in the international hierarchy than treaty law and even “ordinary” customary rules.’Footnote 80
Despite this judicial pronouncement, hierarchical superiority of jus cogens remains a contested issue, particularly so after the ICJ’s Germany v Italy decision on jurisdictional immunities.Footnote 81 Yet jus cogens can have interpretative effects on the system of international law even in the absence of its hierarchical superiority. Notably, neither Article 38(1) ICJ Statute nor Article 31 VCLT create a pre-determined hierarchy of sources and/or norms. The concept of jus cogens has its value as an interpretative systemic element that reflects community values and overrides state centrism and certain classical tenets of international law-making. The concept changes the traditional paradigm of international law as voluntary law and introduces a set of norms that can be legally binding on states even in the absence of their consent. It thus manifests a strong sense of the international community interest that prevails over the will of individual states. However, they have not been given any effects of hierarchical superiority in international judicial practice.
When jus cogens norms are breached, the concept does not create remedies that would trump other international legal obligations.Footnote 82 What jus cogens does is that it prevents a certain obligation to develop either by law-making or subsequent interpretation. For example, Article 53 VCLT would void a treaty by virtue of which two or more states create an obligation to torture, for example, a terrorism suspect. Moreover, jus cogens prevents that the positive obligation under the right to life could be interpreted as an obligation to torture in order to extract information in the so-called ticking bomb scenario.Footnote 83 Such a conclusion would also be in line with Conclusion 20 of the ILC Report on Jus cogens which reads: ‘Where it appears that there may be a conflict between a peremptory norm of general international law (jus cogens) and another rule of international law, the latter is, as far as possible, to be interpreted and applied so as to be consistent with the former.’Footnote 84
International legal doctrine has thus introduced certain concepts that imply the presence of a ‘hierarchical meta system’,Footnote 85 but it appears that Dino Krtitsiotis is right when he concludes that international law does not know how to accommodate these concepts. He argues: ‘Our “international community” is “deep” enough to have conceived of the idea of jus cogens but not deep enough to know what to do with it. It is caught in the perennial mire of something called erga omnes (or obligations owed to the “community” as a whole), and continues to inch toward so-called crimes and offences against the “international order”.’Footnote 86 The problem is that all these concepts envisage a strong sense of community and its values. While such a community sense may well limit the treaty-making capacity of states and influence the interpretation of treaty and customary obligations, these public law elements in international law remain rather limited. It appears that the value-loaded concepts of jus cogens and erga omnes serve a similar purpose as limitations on the freedom of contract in municipal law. In other words, it may well be the case that international law remains a rather shallow system that lacks complexity; but systemic elements are there and shape the interpretation and application of legal obligations stemming from treaties and custom.
2.3.4 The Systemic Elements
General principles of law are a formal source of international law under Article 38(1)(c) of the ICJ Statute.Footnote 87 Unlike obligations erga omnes and jus cogens norms, general principles thus have a clear textual basis for their legal authority as a formal source of international law. Their normative value nevertheless appears to be somewhat undefined. Writers have particularly questioned whether general principles directly generate any international legal rules and obligations.Footnote 88 International treaty and customary international law can create an obligation in the sense that state A shall not do X, and state B shall do Y. It would be difficult to derive such obligations from a general principle of law only and exclusively. As argued by Gleider Hernandez, ‘general principles normally enter judicial reasoning without formal reference or label’.Footnote 89 In other words, general principles of international law are often in the background of reasoning when other sources of international law are interpreted but do not generate direct legal obligations.
In that sense, Hersch Lauterpacht wrote that the concept of general principles of law is ‘in essential harmony with the attitude … of every legal community’.Footnote 90 Notably, Lauterpacht thus saw general principles are an element that underpins the sense of a legal community in international law. The reference to a legal community is very similar to what we understand nowadays under the term systemic integration. International law lacks coherence and characteristics of a legal system if it does not adopt certain internal rules that ensure at least a minimum threshold of its coherence.Footnote 91
Craig Eggett notes in this regard:
The mode of creation of general principles of law is one of the issues where the lack of clarity in comparison with treaties and customary rules becomes very clear. For treaties, the rules of the … [VCLT] set out the formal procedures for signature and ratification, and provide for certain conditions of validity. For the ascertainment of customary rules, the ICJ has built a body of case law stating and clarifying the well-known elements of state practice and opinio juris. There is as yet no such guidance for the ascertainment of general principles of law. Seeking to establish the criteria for the ascertainment of general principles can contribute the establishment of constitutional features in at least two ways. First, there is scope to rely on the concept of the ‘international community’ as a basis for the recognition of general principles. Increased clarity as to international lawmaking processes enhances its systemic coherence. Second, greater reliance on this source could allow for the creation of rules that are not exclusively dependent on the consent of states, and so seek to serve the interests of the community as opposed to solely those of states.Footnote 92
It has been argued in this chapter that obligations erga omnes and jus cogens norms provide for a very rudimentary systemic public law element in the private law structure of public international law. Both concepts are built on the understanding of there being an international community underpinned by a minimum threshold of public community values. The role of general principles of law is even more complex in this regard. They bring elements of both public and private law into the international legal system.
International judicial bodies had to import to international law a great deal of procedural principles in order to be able to exercise their judicial function.Footnote 93 The underlying treaties that create such judicial bodies do not and cannot anticipate every possible procedural issue that may arise in the future, and reliance on the general principles of international procedural law is thus instrumental. International criminal tribunals need to resort to general principles of criminal law in their work.Footnote 94 With respect of international treaties, certain private law analogies (e.g. general principles of contract law) maybe used in the process of interpretation and application.Footnote 95
Discussing the rule of law principle, Thin argues that systemic integration of this principle:
[O]pens the door to a very different role for international courts and tribunals. The end point of this reasoning is to see international courts and tribunals, or at least some particular courts and tribunals, as organs of the international community. They perform a systemic role in the interest of the community in the rule of law rather than purely in furtherance of individual state interests. This way we see the court(s) as above and beyond the will of states; as a form of public authority. Suddenly, the purpose of the judicial body is not only the settlement of the dispute, but also to ensure and enforce compliance with the law more generally …. Such an aim could underlie broader functions, such as the existence of a broader advisory capacity or even judicial law-making in a gap-filling capacity.Footnote 96
In other words, the application of general principles of law enables international courts and tribunals to act as systemic judicial bodies of the international community rather than mere dispute settlement mechanisms akin to private law arbitration.
Eggett argues that ‘general principles of law play a central role in the operation of the international legal system, so much so that they constitute systemic elements of international law’.Footnote 97 Indeed, it is well-established in doctrine and practice that individual sources of law cannot be read in isolation and need to be interpreted in line with other applicable sources in a particular situation.Footnote 98 The general principles of law are instrumental in the process of fitting the puzzle pieces together. It is sometimes difficult to distinguish the effects of the general principles of law in the sense of Article 38(1)(c) of the ICJ Statute from those under treaty or even customary international law. This is because a number of general principles are in any case also elaborated in treaties or have also become customary (e.g. pacta sunt servanda and lex specialis) under the VCLT and customary law of treaties. But it is not uncommon in international law that a certain legal rule or doctrine may follow from more than one source of law. After all, it is quite common that multilateral treaties overlap with custom. Although Article 38(1)(c) of the ICJ Statute is not their only point of entry into the international legal system, the general principles of law have an important systemic function in the interpretation and application of the rules and obligations of international law.
The ILC has made an interesting terminological choice in Draft conclusion 2 of the Draft Report on General Principles of Law, which reads: ‘For a general principle of law to exist, it must be recognized by the community of nations.’Footnote 99 The ILC explained that
Draft conclusion 2 employs the term ‘community of nations’ as a substitute for the term ‘civilized nations’ found in Article 38, paragraph 1 (c), of the Statute of the International Court of Justice, because the latter term is anachronistic. The term ‘community of nations’ is found in article 15, paragraph 2, of the International Covenant on Civil and Political Rights, a treaty to which 173 States are parties and which is thus widely accepted …. By employing this formulation, the draft conclusion aims to stress that all nations participate equally, without any kind of distinction, in the formation of general principles of law, in accordance with the principle of sovereign equality set out in Article 2, paragraph 1, of the Charter of the United Nations.Footnote 100
The ILC’s terminological choice is thus not accidental but derived from certain other international legal instruments. The terminological choice of the ILC seeks to stress the diversity of legal systems represented in the world:
The use of the term ‘community of nations’ is not intended to modify the scope or content of Article 38, paragraph 1 (c), of the Statute of the International Court of Justice. In particular, the term does not seek to suggest that there is a need for a unified or collective recognition of a general principle of law, nor does it suggest that general principles of law can only arise within the international legal system. Furthermore, the term ‘community of nations’ should not be confused with the term ‘international community of States as a whole’ found in article 53 of the Vienna Convention on the Law of Treaties, relating to peremptory norms of general international law (jus cogens).Footnote 101
The ILC here clearly subscribed to there being an idea of a community at the international level. The distinction between the ‘community of nations’ and ‘international community of States as a whole’ seeks to stress that general principles of law can be derived from all legal systems of the world, and the uniformity of state practice and/or general acceptance requirement is inapplicable to this source of international law. The concept of general principles of law in the doctrine of sources of international law thus reflects the idea of an international public community and supra-national law-making beyond state-centrism.
2.4 Conclusions
Public international law operates in a private law paradigm. In its essence, this is a system of contract-like and tort-like relations between states. The word ‘public’ in public international law is a misnomer. A comprehensive public law framework is absent in this system. In order for the system to function, however, some rudimentary elements of public law have been introduced to help regulate the private law relations between states. The interpretation technique of systemic integration is a tool for building a rudimentary public law structure in the system of international law. The systemic public law concepts at work here are general principles of law, obligations erga omnes and jus cogens norms.
It remains debatable whether the general principles of law as a source of international law are able of generating any direct legal rules and obligations. Their function has been said to be primarily systemic in nature. They are often lurking in the background when other sources of international law are applied and interpreted. They also provide coherence to international law and mitigate against Hart’s assertion of international law being a non-system. Reliance on general principles has been particularly important in those situations where treaty and customary law was rather thin (e.g. to prevent non liquet in international adjudication)Footnote 102 or two or more obligations stemming from either treaty or custom appear to be in conflict.Footnote 103 As Thin argues
Despite Hart’s rather infamous comments to the effect that international law is better described as a ‘mere set’ of rules rather than a system, there is increasing acceptance of the systemic nature of international law. The comparative lack of institutional development and coherence is no longer as great a barrier, and the essential ‘rules of the game’, as noted above, are increasingly accepted as equivalent to the source of essential authority found in domestic systems.Footnote 104
The concept of jus cogens is probably nothing different than an international analogy to public law limitations on the freedom of contract. They provide for a limitation on state consent and prevent that certain obligations could develop that would offend against the minimum threshold of an international public order. Obligations erga omnes presume the existence of an international community or international society and create a vertical (public law type) relationship between states and the community. This relationship, however, is rudimentary and not underpinned by a comprehensive political and constitutional theory the way this is ordinarily done in municipal settings.
It is thus at least premature to analyze international law through the lens of constitutionalism. What international law does have, however, are certain very rudimentary elements of public law without which the interpretation and application of treaties and custom would be difficult in practice. Such elements are not derived from a comprehensive constitutional and political theory of the international community. They rather come from the concept of general principles of law, obligations erga omnes and jus cogens norms, and enter international legal reasoning through the interpretative technique of systemic integration. International law is certainly not a very comprehensive legal system, but general principles, erga omnes obligations and jus cogens norms add certain systemic qualities to it and ensure that international law is not a non-system.
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