Although the international legal system lacks centralized authority and formal constitutional quality, the emergence of various legal concepts suggests that international law is characterized by some form of normative hierarchy. The principal impulse that spurred the debate over a hierarchical order of international norms has been the incorporation of jus cogens into international law in the 1960s, which endows certain norms with distinct legal qualities, thereby elevating them to the ‘top’ of the international normative order.Footnote 1 These peremptory norms,Footnote 2 and the value-laden content they carry, are considered to be so important to the international community as a whole that they are non-derogable and apply to all states, regardless of whether they have consented to them.
The concept of jus cogens has been exhaustively discussed by international legal theorists and practitioners. Yet, critical questions regarding both its nature and existence persist. Part of this controversy is reflected in and can be attributed to the insufficient jurisprudential foundations on which the legal debate about peremptory norms rests. Due to its focus on formalism and abstract notions of rights, international legal theory has been unable to provide convincing explanations for the way in which certain norms gain superior status. In particular natural law, the most common justification for the existence of superior norms, suffers from empirically removed presumptions about a normatively cohesive international community.
It is here where the discipline of International Relations (IR) enters the picture. Making sense of the normative complexity of international life, and understanding how the global institutional architecture accommodates different normative visions, has become a major task for international normative theorists and those interested in sociological approaches. In particular, scholars working within the theoretical tradition of the English School have generated a wealth of literature dealing with the emergence, nature, and transformation of shared norms, values, and institutions. Drawing on the classical British institutionalism of Bull (Reference Bull1977) and Wight (Reference Wight1991), as well as more recent constructivist thought, these works explore the constitutional structure of international society and the way in which its rules and principles define the fundamental conditions under which global interactions take place (e.g. Reus-Smit Reference Reus-Smit1997, Reference Reus-Smit1999; Ralph 2007).Footnote 3 They show that even under the condition of anarchy, international society has established constitutional-like norms and institutions that constrain the exercise of power and create expectations about what actions are permissible in global life (e.g. Clark Reference Clark2005). In doing so, they not only highlight the complex interplay between law and politics (e.g. Reus-Smit Reference Reus-Smit2004), but also understand international law in terms of the normative and ethical claims that shape its structure and content. What these works suggest, then, is that the nature of peremptory norms is inherently legal, ethical, and social, requiring a more holistic treatment then international jurisprudence currently offers.
Drawing on insights from social constructivism and English School theory, the purpose of this article is to develop a sociological conception of jus cogens that shows why and how international society considers certain norms as hierarchically superior. Such a sociological treatment, I wish to suggest, is necessary because many of the puzzles surrounding jus cogens (e.g. why are certain values more important than others? Why does a social group such as international society consider certain rules for behaviour as universal and compulsory?) cut across disciplinary boundaries. The goal of the article is thus to engage IR theorists in thinking about how norms with superior normative force emerge in international society, and to help lawyers to understand the existence of peremptory norms beyond international law. While this does not automatically result in a more coherent legal theory/practice of jus cogens, it can provide lawyers with a more holistic understanding of the concept and the silent assumptions that underpin its nature and function.
The principal argument underlying this article is that jus cogens should not be treated as a formally imposed concept, as lawyers tend to do; instead, it is best understood as a social arrangement that demarcates the normative boundaries of international society. Rather than emanating from a metaphysical source or formal treaty, jus cogens is a manifestation of the social and normative organization of international society and the way in which we think about its ethical content: the fact that the society of states regards certain norms such as the prohibition of genocide or the prohibition of slavery as mandatory, overriding other rules and binding all states, tells us something about the kind of international society we live in and the nature of its normative aspirations and ethical dilemmas.
The article begins by looking at the debate about relative normativity in international legal theory and practice, focussing on the concept of jus cogens as the key element of a hierarchy of norms in international relations. The purpose here is not to review all the previous studies, but to find common themes and highlight their respective explanatory strengths and deficiencies, in particular with regard to international practice. The second section then explores the relationship between law and international society, thereby establishing the rationale for an alternative, sociological perspective, before turning to the issue of normative sources. From here I develop two logics through which international society constructs its normative character and show how they can be utilized for thinking about the function and nature of peremptory norms. The first logic is rooted in a solidarist account of shared order values and depicts jus cogens as a manifestation of cosmopolitan values. The second finds its genesis in a pluralist conception of international society that places diversity and respect at the top of its value hierarchy.
Jus cogens international law: conceptual foundations and theoretical debates
In a seminal article trenchantly critical of an emerging normative differentiation of legal rules, Weil (1983) identified three ‘hierarchical’ tendencies in the international legal system: the emergence of soft-law and a corresponding legal discourse on the effects of UN General Assembly resolutions;Footnote 4 the distinction between obligations owed to the international community as a whole (also referred to as obligations erga omnes) and obligations owed to individual states, exemplified in the International Law Commission’s (ILC) distinction between ‘normal’ internationally wrongful acts, which it called ‘delicts’, and extremely severe violations of international law, which it termed ‘crimes’ (Yearbook of the ILC 1976, 95–112);Footnote 5 and the formal recognition of the concept of jus cogens in the 1969 Vienna Convention on the Law of Treaties (VCLT). We should add a fourth indicator here, which Weil did not discuss, namely the UN Charter, which posits that its provisions prevail over ‘ordinary’ rules of international law (UN Charter Article 103). Taken together, these legal doctrines and concepts provide the basis for the claim that there exists a differentiation of the normativity of legal norms in international relations.
This article focusses on the upper extreme of normative hierarchy in international law, that is, the concept jus cogens. Many of the conceptual and theoretical debates about a normatively differentiated international legal order converge upon the concept, and it gives rise to the most compelling, and for my purpose most relevant, arguments in support of the existence of a category of higher order norms. As far as I am aware, there is hardly any work on the structural transformation of the international legal system, whether theoretical or empirical, that does not make reference to jus cogens. Constituting by definition an idiosyncratic category of universal, non-derogable, and mandatory norms, international lawyers see the inclusion of jus cogens in the VCLT as the ‘primary impulse’ for the structural change of the international legal system from a horizontal to a vertical system of law (Bianchi Reference Bianchi2008, 494).
The concept of jus cogens stipulates the existence of certain international norms from which no derogation is permitted. As Kolb (Reference Kolb2015, 3) explains, ‘jus cogens is a legal technique which attaches to a series of norms to confer on them a particular resistance to derogation’.Footnote 6 In international law, these so-called ‘peremptory norms’ are considered to be universal and mandatory, binding all members of international society. The concept has been formally enshrined in positive international law in Article 53 of the 1969 VCLT:
A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. For the purposes of the present Convention, a peremptory norm of general international law is a norm accepted and recognized by the international community of states as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.
The introduction of jus cogens to positive international law has been celebrated as a major breakthrough in the institutionalization of the interests of the international community as a whole. Typically traced back to the pre-World War I belief that a common set of universal principles should govern ‘civilized nations’, the concept’s formal development during the second half of the 20th century is seen as a clear and unequivocal statement in support of the existence of certain ethical considerations and moral goals shared by all members of international society (Shelton Reference Shelton2006, 295–97). Though legal theory has focussed almost exclusively on jus cogen’s existence post-1945, the idea that certain higher order norms exist beyond the will of legal subjects is as old as international society itself. Meaningful precedents of peremptory norms can be found in the Roman law distinction between jus strictum and jus dispositivum, as well as in the thought of 17th and 18th century classical legal theorists such as Emmerich de Vattell and Hugo Grotius.
Looking at both the conceptual development and formal establishment of jus cogens, it becomes readily apparent that the essence of peremptory norms is a quest for safeguarding the moral integrity of international life through law. Verdross (Reference Verdross1937, 572), the founding father of the concept of jus cogens, was perfectly clear about the supreme ethical motives that drove his work:
This prohibition [Jus Cogens], common to the juridical orders of all civilized states, is the consequence of the fact that every juridical order regulates the rational and moral coexistence of the members of a community. No juridical order can, therefore, admit treaties between juridical subjects, which are obviously in contradiction to the ethics of a certain community.
Enshrined in the concept of jus cogens are thus certain discrete norms that possess compulsory qualities irrespective of state consent; treaties that violate rules belonging to jus cogens are to be regarded as null and void. Peremptory norms, Verdross (Reference Verdross1966) specified later, can be distinguished from all other rules of international law by the fact that the latter is relative, creating obligations and rights that concern only individual states inter se, while the former is absolute, satisfying interests of all states. Relying on this notion, the VCLT transformed, at least formally, international law into a vertically differentiated system of rules with peremptory norms at the top, and the validity of any other international rule depending upon its compliance with the hierarchically higher peremptory norm.
The superior status of certain norms becomes even more evident when related to the obligations (beyond treaty making) that belong to them. All peremptory norms are said to have erga omnes effects (Bassiouni Reference Bassiouni1996; Kadelbach Reference Kadelbach2006; De Wet Reference De Wet2013). That is, they contain obligations that are owed towards the international community as a whole, as distinct from obligations states owe towards individual members by way of treaty. This is because these rules are considered so fundamental, and the rights involved in them are so significant, that all members of the international community have a legal interest in upholding them. While the relationship between erga omnes and jus cogens is not entirely clear, the fact that peremptory norms give rise to obligation directed to the international community as a whole has been widely endorsed by states, organizations, and scholars (Byers Reference Byers1997).
Notwithstanding its formal recognition, many commentators have raised objections concerning the concept’s ineffectiveness (Schwarzenberger Reference Schwarzenberger1965; Schwelb Reference Schwelb1967), emptiness (Weisburd Reference Weisburd1995), and empirical insignificance (D’Amato Reference D’Amato1990).Footnote 7 Although there is a wide agreement among scholars on the peremptory status of the prohibition against genocide, torture, aggressive war, racial discrimination, and the right to self-determination, no definitive list of peremptory norms exists. A great deal of the confusion over the rationale for jus cogens can be traced back to the vague theoretical basis on which the concept rests. Both of the great jurisprudential schools – natural law and positivism – suffer major deficiencies as theoretical foundation for peremptory norms, which, in turn, has important implications for their empirical relevance.
The concept of jus cogens was developed under the strong influence of natural law.Footnote 8 Many legal commentators involved in the drafting process of Article 53 of the VCLT asserted that jus cogens rules owe their superior normative status to their inherent moral authority. Lauterpacht (Reference Lauterpacht1970, 90–93), for example, contended that peremptory norms derive their higher legal status from both international morality and general principles of state practice. In a similar vein, the ILC’s member Yasseen argued that the only meaningful criteria for distinguishing between ordinary rules drawn from custom or treaties and norms belonging to jus cogens was to determine whether the rules were ‘deeply rooted in the international conscience’ (Waldock 1963, 63). Assertions of peremptory norms being anchored in natural law are still widespread across the literature. Henkin (Reference Henkin1981) and Sohn (1982), for example, claim that international rules such as the non-use of force and the prohibition of slavery obtain their higher authority through both their intrinsic normative weight and rational appeal. More recently, Dubois (Reference Dubois2009) offered a natural law explanation that links the authority of jus cogens to the greater public good. Following his argument, the status of peremptory norms ‘stems from the ability of these norms to guarantee a number of the basic goods and fulfill the demands of practical reasonableness’ (Dubois Reference Dubois2009, 174). Natural law explanations raise a number of well-documented difficulties. Perhaps most notably, natural rights-based accounts are criticized for conflating subjective moral norms with objective general principles of international law (Hart Reference Hart2012). It is indeed extremely difficult to automatically deduce or verify concrete legal rules from a metaphysical source such as international morality (Boyle and Chinkin Reference Boyle and Chinkin2007). Natural law theorists are thus left with little means to specify the content and scope of peremptory norms, or the process by which a particular norm asserts peremptory status.
In order to countenance overtly subjective considerations about the innate nature of rights and values in judicial practice, scholars such as O’Connell (Reference O’Connell2012) and Tomuschat (Reference Tomuschat1993) suggest to couple natural law justifications for jus cogens with an examination of states’ normative practices and customary law, respectively. Others such as Byers (Reference Byers1997) have placed jus cogens entirely in the hands of states, understanding jus cogens as a form of customary international law that has rendered its peremptory status through opinio juris and state practice. Deriving status and content from state consent seems to circumvent one of the major problems associated with natural law theories; by arising from international custom, rather than metaphysical sources, peremptory norms are able to obtain legitimacy through the control states exercise over the emergence and change of peremptory norms.
Although customary accounts seem to bridge a positivist international law theory based on state sovereignty and consents with the main characteristics of peremptory rules such as non-derogability and fundamental status, using customary law to explain peremptory norms bears some difficulties. Most importantly, it is not immediately clear how any positivist conception of norms deriving its authority from the consent of sovereign states does exclude any considerations of legal exceptions made through persistent objection (Dubois Reference Dubois2009, 140). Indeed, a reasonably coherent positivist account of jus cogens would not only require a kind of ‘double consent’, that is, a recognition of the norm as custom and an acceptance that this norms possesses superior, non-derogable qualities; but also a far more widespread consent than required by ordinary norms of custom. Those requirements are certainly not impossible to achieve – it is usually the case that the majority of states consent silently by not expressively objecting – but it is questionable whether state practice alone can explain the ethical superiority typically associated with jus cogens. Tasioulas (Reference Tasioulas1996) thus seeks to derive the universal and non-derogable qualities of peremptory norms from a communitarian-inspired version of customary law that down-grades the importance of general state practice in favour of opinio juris and value-laden social context. As I will argue later, this move is interesting for the purpose of charting a sociological account, not at least because it links universal international law to shared world order values. Yet, even an approach based on a ‘sliding-scale’ interpretation of custom has to resort to some kind of natural law justification when explaining why certain norms retain a universal scope irrespective of non-consent and persistent objection (e.g. Tasioulas Reference Tasioulas1996, 100–04).
Despite their individual differences, most justificatory theories share a common focus in that they are almost exclusively concerned with the formal character of jus cogens, paying little attention to its existence beyond international law. As a consequence, this has limited the theoretical debate to a seemingly unresolvable dispute about definitions, and legal sources and criteria for identifying peremptory norms, cutting out other important aspects regarding the concept’s social meaning. Petsche (Reference Petsche2010, 237) neatly summarizes the narrow character of the debate, maintaining that all ‘discussions of jus cogens share a common approach, namely the fact that their criticism of, support for, and overall analysis of jus cogens invariably relate to the practical usefulness of this concept (…) as a rule of international law’. According to Shelton (Reference Shelton2006, 292), however, jus cogens’ impact on international dispute settlement and state practice has been marginal, with courts giving little effect to assertions of peremptory norms. In a recent survey of the literature and practice surrounding jus cogens, Saul (Reference Saul2015, 34–38) points to an upbeat in courts’ willingness to engage with the concept, citing the International Court of Justice’s reference to the jus cogens status of the prohibition against torture in Belgium v. Senegal as an indicator. That said, his analysis ultimately confirms that almost 40 years of scholarly and judicial work had produced little progress in the doctrine of jus cogens identification.
While far from stipulating concrete methods for identification, I suggest that a sociological IR approach can help to remedy the insufficient theoretical basis upon which the concept of jus cogens has been built. By avoiding an excessive focus on the concept’s legal effects, function, and sources, it leads us to highlight the social and normative foundations upon which the concept rests. In doing so, it makes room for an enquiry into the relationship between jus cogens and the society in which it operates, emphasizing the role peremptory norms play beyond international law.
In developing my argument, I join a number of other constructivist scholars who have sought to bridge the disciplinary divide between law, sociology, and politics. Challenging the liberal-positivist approach to ‘legalization’ that casts law in terms of discrete, express agreements,Footnote 9 they have called for a fuller appreciation of what law in international relations is and how it affects behaviour. They conceptualize international law as a social phenomenon embedded in and shaped by the practices, beliefs, ideas, and traditions that constitute the society of states (e.g. Brunnee and Toope Reference Brunne and Toope2000; Finnemore and Toope Reference Finnemore and Toope2001; Reus-Smit Reference Reus-Smit2004). In Allott words:
Law forms part of the self-constituting of a society. The legal self-constituting of society co-exists with other forms of social self-constituting: self-constituting in the form of ideas and self-constituting through the everyday will and acting of society-members. Law is generated, as a third thing with a distinctive social form, in the course of the ideal and real self-constituting of society, but law itself conditions those other forms of constituting (Reference Allott1999, 32).
This attention to the social nature of law is helpful for thinking about jus cogens, because of the way in which it draws connections between the different types of normativity at work. Whereas the codification of jus cogens through the VCLT, understood as a social process, seems to be the product of the ideational realm of international society, customary law grounds the identity and substance of peremptory norms in context, meaning, and practice.
One needs to be careful, however, not to equate state practice and opnio juris – the two principal epistemological markers for custom in international legal theory – with the notion of social practice found in the IR theory literature. For constructivists, practice is a wider a social activity that includes inter alia historically evolved institutions and traditions, tacit understandings of silent rules, shared points of reference, and the construction of cognitive-symbolic structures. The international legal system is a key institutional site in the evolution of practice, but, as Navari argues, ‘both practical understandings – the knowing how to prompt and respond – and the teleoaffectivities lie beyond law’ (Reference Navari2011, 623). Courts, cases, and the articulation of legal obligation via opinio juris are undoubtedly important empirical manifestations of and proxies for practice, but as a social form, (customary) law is first and foremost expressed via meaningful participation in the daily re-production of international society, not by some specific act or will (Allott Reference Allott1999, 39).
Framed in this way, there is no radical discontinuity between social and legal forms of normativity. Law is created and applied in a distinctive manner, as constructivists would argue (e.g. Kratochwil Reference Kratochwil1989, Reference Kratochwil2014; Finnemore and Toope Reference Finnemore and Toope2001), but rules and other express agreements are ultimately manifestations of, rather than external to, the more implicit social and normative fabric that structure international society. The conceptual relationship between legal and social forms of practice is perhaps most clearly developed in Brunnee and Toope’s (Reference Brunne and Toope2000) interactional account of international law. Drawing on constructivist thinking, they see the legitimacy of law deeply rooted in the social context against which legal subjects interpret norms. As they explain ‘it is largely through institutionally shaped rhetorical practices, and acceptances of reasoned argument, that law emerges from broader social practice’ (Brunnee and Toope Reference Brunne and Toope2000, 51). This is an astute observation, because it analytically separates the rhetorical practice of law from the social practice that constitutes the background against which law is (re)-produced, without erecting hard boundaries between the two.
To get to grips, analytically, with the social dimension of jus cogens, the next section establishes a conceptual link between law and society. The approach is predicated upon the idea that peremptory norms do not assert special status simply because they should exist, but because they are functional to the (re)-production of social relations among states.
Towards a socio-functional approach
Any system of law is invariably linked to its societal context, and international legal theorists and IR scholars alike have long acknowledged the need to relate the exposition of legal issues to the social conditions in which the law operates.Footnote 10 The nature of the relationship between law and society in the international domain is, of course, in many respects idiosyncratic. Most evidently, as James (Reference James1973, 65) notes, it is ‘the lack of government, the absence of central authority and the concomitant dispersal of authority’ that distinguish international from domestic society. Consequently, because the international legal system lacks institutions capable of implementing a legal order independently from the consent of its legal subjects, international law, of all law, is most closely related to and dependent on the social structure of the society in which it operates (Huber Reference Huber1928). For international law to exist, states themselves have to establish an institutional architecture dense enough to carry, and to some extent enforce, legal rules and moral standards. Phrased in the classical English School terminology of Bull and Watson (Reference Bull and Watson1984), they must leave the sphere of ‘international system’, in which interaction is purely mechanistic, anomic, and power driven, and form an ‘international society’ based on a set of common institutions regulating social, rule-governed interaction.Footnote 11
Therefore, English School theorists consider the existence of law in international relations, and more specifically the fact that we can observe a general adherence to rules of law, fundamental to the existence of international society. Mayall, for instance, identifies international law as ‘the bedrock institution on which the idea of international society stands and falls’ (Reference Mayall2000, 94). Similarly, Nardin holds that ‘international society exists to the extent that states understand themselves to be related to one another as subjects of common rules’ (Reference Nardin1998, 20).Footnote 12 Besides providing evidence for its existence, law plays an important role in explaining the very nature of international societies. As hinted above, the analytical significance of international law for English School theory lies in the claim that the legal system mirrors the normative content of international society’s social structure. Coming from a sociological angle, English School theory then seeks to infer arguments about the nature of international society through the analysis of the structure, content, and development of international law. As Wilson (Reference Wilson2008) recently observed, English School scholars have spent time and effort to show that international law always reflects the society from which it emanates, and that we can only make sense of international law by contemplating the distinct character of international society. Conversely, international legal scholars point out that the specific functions of international law, including its imperfections, correspond for the most part to the structural features inherent in international society (Salcedo Reference Salcedo1997).
If one accepts the argument that the structure and normative content of the international legal order is a manifestation of deeper-seated moral beliefs and social ordering practices, then the question of jus cogens is about the norms and values international society selects in order to define what constitutes legitimate membership, and what this society ultimately considers as rightful and permissible action. By formally stating the absolute impermissibility of certain behaviours, peremptory norms have a constitutional effect on international social order; they set out the fundamental and non-derogable rules according to which states interact. For an actor to breach these rules essentially means placing oneself outside the normative framework of international society and the conventions which establish its normative boundaries.
In that they are the foundations of the social order of international society, embodying the basic ordering principles, peremptory norms come close to Bull’s (Reference Bull1977, 65–66) category of ‘constitutional normative principles’. A number of IR scholars not necessarily associated with the English School have thought in similar terms about jus cogens rules. Onuf (Reference Onuf1994, 13–14), for example, drawing on Hart’s distinction between primary and secondary rules, argued that the latter operates as international society’s constitution by laying out criteria for membership and ‘conferring and limiting power’. We can also hear clear echoes of Onuf’s argument in Ralph’s (2007) study of the International Criminal Court. Like Onuf, he suggests that the moral foundation of international society rests on a number of constitutional rules precisely because they identify states as legitimate members and place limitations of their actions. In modern international law, Ralph observes, ‘such rules are considered jus cogens’ (2007, 15).
Although constructivist scholars have acknowledged jus cogens’ constitutive dimension, they have failed to fully appreciate its complexity and the role it plays in (re)-producing societal relations among state actors. To tease out jus cogens’ social nature and function, as distinct from its legal understanding, I conceptualize jus cogens as part of international society’s constitutional structures. Following Reus-Smit (Reference Reus-Smit1997, 566), I define constitutional structures as ‘coherent ensembles of intersubjective beliefs, principles, and norms that perform two functions in ordering international society: they define what constitutes a legitimate actor (…), and they define the basic parameters of rightful state action’. Because these normative complexes are analytically and anthropologically prior to other norms and institutions, providing the basis for the political organization of international society, they pre-structure states’ social identities and their institutionalized practices (Reus-Smit Reference Reus-Smit1999, 26–40).
If we think about peremptory norms as part of the modern global constitutional structure, the very idea of international society becomes rooted in the recognition of being bound by the ‘highest’, most essential norms, values, and principles, whatever they may be, and by the obligation its members feel to act in accordance with them. This is not to say that the existence of international society depends on all states adhering to these peremptory norms, rules, and principles all the time – a key feature of norms, at least from a sociological perspective, is that they are, to a point, counterfactually valid. But, as Reus-Smit (Reference Reus-Smit1999, 26–28) notes, it is difficult to imagine, how the society of states can exist as a durable social group without a shared belief in and commonly felt obligation towards the basic normative background structures concerning legitimate membership and rightful behaviour. In other words, without mutually recognizing the higher, peremptory quality of certain norms and values, strategic and self-interest orientated behaviour is likely to replace meaningful social interaction, ultimately threatening the society of states. This is, as Reus-Smit (Reference Reus-Smit1999, 28) explains, because reasoned agreements, resulting in stable patterns of predictable behaviour, rely heavily on ‘preexisting, mutually recognised higher order values [that] are considered valid’. In fact, if states cannot reach some more or less stable agreement on which norms are to be considered primary for rightful behaviour and legitimate statehood, international society cannot function, because it is difficult to see how it can be constituted as an ontological entity in the first place.Footnote 13
A sociological perspective then couches an explanation of jus cogens in functionalist terms. It sees jus cogens as an objective feature of international society that contributes to its social cohesion and thereby to its continuity and survival. Crucially, such an approach links the legitimacy of higher order norms in international law to the wider social function they perform in international society: jus cogens is legitimate because it is functional for demarcating the outer boundaries of the basic normative background structures of international society. In other words, accounting for jus cogens’ legitimacy as a universally binding element of the global normative order (international law) and explaining its effect in relation to its social environment (international society) become two sides of the same coin.
The notion of function has featured prominently in the social sciences (e.g. Parsons Reference Parsons1951; Merton Reference Merton1957), as well as other academic disciplines, including the social sciences, biology, psychology, and technology. Social functionalists are united in their endeavour to show that all social items (e.g. norms, institutions, roles, authority structures) emerge and persist because they are useful to the social system in question. However, to assert that the presence of certain internal or external activity of some subsystem is required by the overall design of the social system in question is a description, not an explanation proper (Mahner and Bunge Reference Mahner and Bunge2001, 83; see also Wouters Reference Wouters1999). It is clear that the preceding developments only amount to functional account rather than a functional explanation, in the sense that they merely demonstrates that peremptory norms are required by the overall design of international society. To fully understand the social nature and function of jus cogens in international society we need to address two interrelated questions: How and why jus cogens has become part of international society’s normative order; and what is the social and normative basis that presuppose its superior legal qualities? The bulk of (legal) research has focussed on the former question, and, as shown earlier, there is a great deal of work documenting the concept’s development in international law. By comparison, jus cogens’ social and normative basis has largely gone unacknowledged, and we know little about why international society regards certain norms and values as superior, and not others. Yet, without a clear understanding of what the dominant interests and values of international society are, it is difficult to see how jus cogens can be anything more than just a theoretical construct with symbolic relevance. As Christenson rightly asked: ‘How can a system-bound norm, meant to protect the [society’s] legal order, limit that legal order without some broader normative criteria?’ (1987–Reference Christenson1988, 593). The remainder of this article seeks to explicate the normative/ethical foundations of jus cogens. In the process it challenges traditional natural law explanations, and it stresses the social and ideological diversity of international society.
Bringing values back-in
As the VCLT shows, jus cogens is a distinct category of international norms, possessing unique, authoritative legal qualities that universally apply to all members of international society. The interesting question is what exactly distinguishes these rules from other international norms. Looking at the norms frequently characterized as peremptory in character, it seems that the superior status of jus cogens rules is closely related to the normative content that is vested in them. Put broadly, certain norms sit at the pinnacle of the global normative order because they carry a normative weight and/or function that is heavier and/or normatively more important than those of ordinary rules. The prohibition of slavery, the prohibition of torture, or the prohibition of genocide are all expressions of ethical considerations about human dignity and the prevention of bodily harm; and they seem to involve moral principles concerning the treatment of human individuals that are more immediate, more visible than the ones invoked in, say, international trade norms.
So where do we search for the sources of the extraordinary qualities of jus cogens norms? The key to understanding jus cogens‘ universal character and normative foundation, I wish to suggest, lies in the notion of ‘international community’ and the nature, scope, and depth of the normative arrangements that constitute its common ethos. Reading both international adjudication and legal theory, it becomes apparent that both the existence and justification of jus cogens, and with it the peremptory qualities of certain norms, is inextricably linked to the ‘international community’. Verdross, for example, draw a clear connection between jus cogens and the ethics of the international community. The prohibition that forbids states to conclude any treaty that violates peremptory norms, Verdross argued, ‘stems from the fact that every juridical order regulates the rational and moral coexistence of the members of a community’ (Reference Verdross1937, 572). The same link has also been conveyed into VCLT, which arguably serves as the key reference point for asserting the existence of peremptory norms. Recall that Article 53 of the VCLT identifies a norm of jus cogens as being ‘accepted and recognized by the international community of States as a whole as a norm form which no derogation is permitted’.
Of the various theoretical approaches to jus cogens it is perhaps public order theorists who come closest to grappling with the normative source from which peremptory norms derive their unique status. For international lawyers such as Christenson (1987–Reference Christenson1988), Orakhelashvili (Reference Orakhelashvili2006), and Rozakis (Reference Rozakis1976), peremptory norms are not only key to the functioning of the international legal system, but also critical to the existence of global public order.Footnote 14 Based on this claim, Orakhelashvili (Reference Orakhelashvili2006, 47) sees the link to community interest as a central to determining the peremptory status of a norm. In order to qualify as a belonging to jus cogens, he argues, the breach of the norm in question must be ‘considered absolutely unacceptable by the international community as a whole’ (Orakhelashvili Reference Orakhelashvili2006, 50).
The relationship between the identity of jus cogens and the international community has also been emphasized in international adjudication. The final judgement of the International Criminal Tribunal for Former Yugoslavia is particularly useful here, because of the way it indicates the various entanglements between the two concepts. Looking at the prohibition against torture, the Tribunal sought to explain its significance by reference to its peremptory status. The judges claimed that the prohibition against torture had evolved into a rule of jus cogens, concluding that ‘the prohibition has now become one of the most fundamental standards of the international community’.Footnote 15 Moreover, according to the Tribunal, the jus cogens nature of the prohibition of torture is, in the words of the final judgement, ‘bestowed’ by the international community.Footnote 16 This is an interesting formulation in so far as it explicitly suggests that the international community as a whole, as distinct from individual interest of its members, is both the beneficiary of jus cogens norms – remember that the purpose of jus cogens is to protect the values of international community (e.g. Verdross Reference Verdross1966, 58; Gormley Reference Gormley1985, 130; Orakhelashvili Reference Orakhelashvili2006, 46) – and the author of the normative weight of those norms.
Although both legal theory and international adjudication frequently make reference to the international community in the context of jus cogens, the nature of their relationship remains conspicuously underdeveloped. Conklin (Reference Conklin2012, 844) and Retter (Reference Retter2011) recently offered accounts that deal precisely with this issue. Both are dissatisfied with the attempts to understand the identity of peremptory norms in terms of treaty or custom, arguing that it is the international community itself that provides the basis for peremptory norms. Above all, Conklin (Reference Conklin2012, 841–44) laments, the traditional source thesis fails to deliver on the key question: Who or what grants Article 53 of the VCLT the power to elevate certain norms above other? Indeed, it appears that any effort that seeks to explain the superior ethical qualities of norms purely in terms of law does offer a somewhat tautological explanation, for it nests one normative source (peremptory effects) within the other (jus cogens status).
The idea that jus cogens originates from the international community has, at least from a theory-building perspective, big implications, because it urges us to re-think the way in which the source and legitimacy of jus cogens, and to some extent the very existence of a stratified global legal order, can be traced back to international law itself. Conklin (Reference Conklin2012, 860) links the higher order qualities of peremptory norms to the socio-cultural ethos of the international community, which he rightly sees as ‘analytically and experientially prior to states’ consent’; whereas Retter sees the superior status of certain norms as ‘arising from the normative commitments that states make by necessary implication for the achievement of the shared objectives and goods of the international community’ (Reference Retter2011, 537). The key problem of both accounts from a normative perspective, however, is that they do not go deep enough. In the end, we never get to know what the substantial content of Conklin’s alleged social-cultural ethos is, or where we should look for Retter’s conception of ‘common good’. One is therefore left guessing as to why a specific norm protects the ethos of a community, or why the international community bestows certain norms with universal qualities and not others. Although Conklin notes that jurists are too often ‘satisfied with a list of norms which are continually repeated as peremptory in international law rhetoric’ (Reference Conklin2012, 840), I am sceptical as to how these works can escape this fallacy – without an understanding of the substantive value content of community ethos, one cannot determine which norms are key to its protection.
Establishing an explicit link between the creation and nature of normative arrangements and substantive considerations of the ethics and morality of the society in which it works is a crucial move in understanding jus cogens. Tasioulas (Reference Tasioulas1996), who is more concerned than most with the normative aspect of a stratified international legal order, has stressed the key role world order values play in the process of ranking legal norms. Stressing the centrality of shared values for the formation of norms with universal appeal, ‘it is substantive value judgements regarding the comparative world order importance of norms’, to borrow Tasioula’s words, ‘that furnish the rationale for upgrading their status or enhancing their scope’ (Reference Tasioulas1996, 88). This seems to vindicate the idea that any conception of jus cogens presupposes a conception of the normative character of international society – and it is this what I want to offer here.
Jus cogens and the normative character of international society: two conceptions
When seeking to examine the common ethos that international lawyers implicate in the development of jus cogens’ norms, the English School’s pluralist-solidarist debate provides a good starting point. The pluralist-solidarist debate is essentially about the depth of value consensus among the members of international society and the potential for collective action that follows from it (Buzan Reference Buzan2004, 141).Footnote 17 In its classical, though certainly oversimplified representation, solidarism and pluralism mark mutually exclusive, diametrically opposed theoretical positions. Pluralist accounts of international society, usually drawn from the works of Bull (Reference Bull1977) and Jackson (Reference Jackson2000), are depicted as state-centric, pessimistic, and exclusivist, focussed on the preservation of a limited set of norms, values, and principles. On this view, sovereignty and non-intervention are both empirical reality and theoretically sacrosanct, as they ensure that a plurality of culturally different political communities can exercise their moral freedoms while peacefully coexisting. The absolute significance of the sovereign nation state for the preservation of order in international life has led pluralists in the past to exclude human beings as subjects of law and sources of moral obligations; and Bull (Reference Bull1977, 64) made it perfectly clear that the ‘rules of coexistence’ on which international society is founded can only be borne out and function within a positive, state-consent-based conception of international law.
Pitched against this normatively rather unflattering view is the solidarist, morally ‘thicker’ account of international society. Usually identified with the works of Vincent (Reference Vincent1986), Wheeler (Reference Wheeler2000), and Hurrell (Reference Hurrell2007), it sees an ethical purpose deeply inscribed in the institutional fabric of international life which transcends national borders, binds individuals together and commits international society to pursue common goals and values. Crucially, on this view, international law must be justifiable in terms of these shared moral values, a notion heavily inspired by the natural law tradition. Contrary to pluralism’s positive international law account, solidarism’s image of international society is firmly grounded in the claim that the content of the international legal system cannot merely be a product of inter-state bargaining, contractual agreements, and self-interest. As Wheeler’s (Reference Wheeler2000) study of humanitarian intervention painstakingly seeks to demonstrate, international society does recognize certain universal notions of human dignity and justice, grants rights to individuals and responds to severe violations of them.
At the risk of stating the obvious, this conceptual bifurcation is somewhat at odds with a global political system in which commitment to sovereignty norms and positive international law exist alongside supranational global governance institutions, transnational courts, and tribunals and notions of human security.Footnote 18 Furthermore, the exclusivity with which solidarism and pluralism have been related to particular models of and developments in international society does not, on the face of it, look very plausible. It is, for example, not clear at all that to argue for the durability of sovereignty as the basic constitutive principles of international relations is to reject the legal or moral significance of human beings that has driven many progressive developments in global governance. The tensions between the basic ordering principles of sovereignty/non-intervention and humanitarian sentiments are, undoubtedly, real and well documented, but theoretically and politically in no way irresolvable. Both conceptions, if carefully considered, open up a whole range of possibilities for thinking about the normative determinants of a common ethos among states, and we should not exclude any of them on prima facie grounds.
Solidarism: the obvious candidate
The majority of work on jus cogens (implicitly) relies on some kind of cosmopolitan, natural law inspired account of ethics, framing the concept’s evolution as part of the wider progressive development of international society towards a space in which identity and community are not state based (e.g. Verdross Reference Verdross1966; Tomuschat Reference Tomuschat1993; O’Connel Reference O’Connell2012). The trend towards relative normativity in international law, Tasioulas (Reference Tasioulas1996, 117) suggests, is best reconstructed by presupposing a ‘communitarian’ account of international society, which takes the ‘community of mankind’ and ‘human dignity’ as the constitutive features of modern public order. It is, indeed, intuitively plausible to situate the concept of jus cogens within a solidarist framework. English School theorists have made a sustained effort to show that diverse social and cultural communities acting within a state-based order can and do give political expression to universal values rooted in the idea of human unity. Linklater’s (Reference Linklater1998, 9, Reference Linklater2002, Reference Linklater2007) work on community and harm in world politics is particularly instructive here, because of the way in which he sees the modern society of states as ‘the first international society which is not destroyed by conquest and war but transformed peacefully by the normative commitment to extending the moral and political boundaries of community’. Linklater complements a moral defence of a Habermasian universal discourse community build around cosmopolitan harm conventions with a sociological account of their realization. In doing so, he grounds natural rights claims in a philosophically sophisticated theory of universal obligations and duties focussed on the eradication of harm.
From a cosmopolitan perspective, then, the collective interests and values peremptory norms are supposed to reinforce and guard are derived from a single answer to the question of what is the most effective and appropriate way of addressing ethical issues related to harm, justice, dignity and political participation, and so forth. If one accepts rights-based cosmopolitanism as an approach to universal norms and obligations, then the list of norms commonly associated with jus cogens seems to be incomplete. Some social, cultural, and economic rights would clearly be contenders for peremptory status, because of the way in which those rights are paramount to both the worth of a human person and her/his ability to shape her/his social and political environment. Cranston’s (1973) controversial philosophical argument that economic, social, and cultural rights are universal in the narrower sense because they refer directly to a particular class of people, and not to all human beings, does not stand up to cosmopolitan scrutiny. It is hard to see where a cosmopolitan inventory of peremptory norms would end, but the right to a standard of health and well-being, for example, are surely a moral necessity according to solidarist ethics. Cosmopolitans such as Pogge (Reference Pogge2010, 1–4) and Blunt (Reference Blunt2015) have repeatedly argued that the causes of global poverty are comparable with crimes against humanity typically associated with slavery and apartheid. It is of course hard to achieve a perfect score in defence of a standard of adequate life and well-being, but from a cosmopolitan point of view it would make no sense to claim that this justifies their exclusion from the interests of international society as a whole. To be sure, such an approach to jus cogens does not require some implausibly high level of common morality that supersedes all particularistic loyalties. But it does work with a cosmopolitan vision of international society that demands that we give the suffering and moral deficits of others equal weight with our own; and it challenges some of the structural conceptualization of international society, most notably the absolute legal and political significance of the state.
Whilst this would add the necessary normative meat to the theoretical bones of jus cogens, juxtaposing normative hierarchy to a solidarist international society does raise a number of problems. Natural law-based accounts have long been criticized for being overtly idealistic, difficult to implement, and insulated from the social and politics realties of modern world politics. Indeed, what is ‘universal’ in relation to global discourse construction, to stick with Linklater’s account, appears to be as difficult as figuring out discussions about natural rights. When the superior legal and moral force of peremptory norm is simply derived from an abstract, rather than concrete, deliberations about ‘good’ and ‘right’, then jus cogens’ role in international relations is prone to being reduced to rhetorical symbolism.
Another challenge every conception with appeal to a single mode of universal reasoning has to face stems from its inherent potential for domination. Those concerns have been raised explicitly in relation to jus cogens, most notably by Koskenniemi (Reference Koskenniemi2005, 197), who claims that appeals to the universal notion of humanity and fundamental rights vested in the concept are in fact an effort to promote Western particular interests by making reference to universal ideas. The tendency to herald enlightenment, science, and rationality as universal benchmarks for human development has featured powerfully in both IR theory and International Law, and it is qualified on historical grounds by sustained periods of Western cultural dominance and expansion.Footnote 19 Whilst decolonization has de-institutionalized immediate forms of dominance, the emergence of United States as the global hyperpower, in particular Washington’s ‘unilateralist overdrive’ after 9/11, revived concerns about a single state ‘laying down the law’ for the rest of international society (Dunne Reference Dunne2003, 315).
Finally, generating a global common interest and ethos among socio-culturally diverse communities with different ethical schemas on the basis of a universal-individual logic is theoretically enchanting, but empirically hard to achieve. It seems fair to say that global life has always been more diverse than solidarists wish to have it. There is also a normative question here: Should we work towards the eradication of competing moral visions and discourse practices, as cosmopolitanism wishes to suggest? There are discordant voices about the normative desirability of a universalized global discourse community which seeks to establish an authoritative consensus around common interests, purposes, and values. Fraser (Reference Fraser1990), for example, has offered a powerful critique of Habermas’ account of a single public sphere. Fraser not only stressed that ‘full parity in participation in public debate and deliberation is not within the reach of possibility’(Reference Fraser1990, 66), but, and perhaps even more importantly, that the existence of a plurality of competing discourses about common good is crucial to balance forces of domination and social-structural inequality.
Pluralism: the counter-intuitive solution
All of this would point towards an account that pays attention to the principles and values that actually circle in international life, and that is rooted in the diverse social, material and political composition of global order. Such an analytical construct must be contingent and disentangled from any definitive judgements about the values and moral purposes of international society. Instead of universalizing ethical hierarchies, and subsequently foreclosing certain constitutional arrangements, an account that revolves around the interface between common ethos and cultural plurality seems to be a desirable alternative.
This opens up ways for a pluralist conception of international society, appreciation of diversity and the politics of difference, and a less ethnocentric, way of thinking about the shared values associated with jus cogens. But can we develop a pluralistic image of common ethos in international society that has enough normative substance to serve as source for norms with superior ethical force and universal appeal? Following Brown (Reference Brown1995, 106), it is plausible to suggest that some of the positive features of international community such as mutual aid and assistance could be realized within a pluralist society of states. He even concedes that pluralism may be the only viable and feasible alternative to a cosmopolitan vision of global human solidarity. Yet, a pluralist association, Brown (Reference Brown1995, 106) notes, remains primarily practical, founded on and preoccupied with the rule of law and not united in the pursuit of any ‘global project’.
Those kind of restrictions are emblematic of pluralism’s traditional image as caricatured in English School theory and beyond. As Bull (Reference Bull1966, Reference Bull1977) sets out a limited normative agenda based on the preservation of social order, deep scepticism about the possibility of shared values across global society has been a recurrent issue in summaries of pluralist accounts of world politics (e.g. Hurrell Reference Hurrell2007, 40–49; Weinert Reference Weinert2011; Keating Reference Keating2013). States, as Bull (Reference Bull1966, 55) espoused the pluralist position, are ‘capable only for certain minimum purposes which fall short of that of the enforcement of law’. It is no coincidence that English School studies of human security, human rights, or the Responsibility to Protect doctrine are almost exclusively solidaritsts’ territory. If we follow Bull’s (Reference Bull1977) and Jackson’s (Reference Jackson2000) theoretical treatments of international society, there are some serious obstacles to developing an understanding of the foundations of value-laden normative arrangements which is not in accord with consensual normative order making and a positive account of international law, respectively. Bull (Reference Bull1984, 13) warned that the global human rights projects without ‘consensus as to their meaning and priorities among them’, has the potential to undermine ‘coexistence among states, on which the whole fabric of world order in our time depends’. It seems as if he speaks directly to the debate about jus cogens, which has hitherto not produced a consensus around its normative content.
The argument that jus cogens is destructive of an international order that promotes peaceful co-existence in the face of difference is also inherent in Weil’s (1983) famous critique of relative normativity in international law. In line with the classical pluralist view, Weil (1983, 418–19) held that any feature of the global normative system which is not in accordance with sovereignty and consensual law making undermines the purpose of this system, that is, to secure co-existence among sovereign and equal states. As I will argue below, such a dogmatic commitment to sovereignty and co-existence as the single, overriding foundational objective of international society misconstrues the pluralist position, because it ignores the crucial function peremptory norms play in an international society marked by different interests and identities. To show that a diverse international society can generate norms with universal qualities vis-à-vis its common ethos, its useful to briefly recall some of the core pluralist assumptions.
Pluralism’s deeply entrenched adherence to the primacy of order, and its corollaries – positive international law, sovereignty, and non-intervention – is usually explained by the political centrality of the nation state in international relations. By exercising political authority and control over territory, the state is portrayed as the ‘bulwark against anarchy’, preventing the outbreak of large-scale social violence in a system constantly on the edge of the abyss of a Hobbesian state of nature (Hurrell Reference Hurrell2007, 27). This argument is usually coupled with a prudential claim about peacefully facilitating difference and co-existence by way of territorializing diversity. The world consists of a multitude of societies, cultures, and social groups, which hold different values, follow different ethical guidelines about what is ‘good’, ‘right’, and ‘wrong’. Through centuries of war, bloodshed and peace settlements, the argument goes, the nation state has established itself as the best solution to the problem of normative polarization, because of the way it divides the social whole into hard-shelled particularistic sovereign communities. Outside state boundaries exist anarchy, uncertainty, and insecurity. Inside those boundaries exist general agreements on the sources and scope of rights and obligations, the legitimacy of institutions, justice, equality, and social conventions. In short, intimately connected to the historical logic of the evolution, and subsequent globalization, of the European state system, pluralism is seen as valuable way to thinking about world politics because it captures a central, inescapable empirical aspect of international relation.
If there is to be prospect in providing a pluralist account of the sources of jus cogens, we need to be able to construct a normative vision around its foundations that challenges the notion that diversity is a state-based ideal. To be sure, such a vision does not need to be cosmopolitan, but it has to be strong enough to animate a society of sovereign states to develop a common ethos deemed worthy enough by its members to subordinate their particularistic national interest to certain universal norms. The normative basis for such an ethos finds its genesis in Williams’ (Reference Williams2005, Reference Williams2015) endeavour to recuperate pluralism as a philosophically sophisticated, non-statist theory. Contrary to what is often assumed, Williams (Reference Williams2015) shows that a commitment to pluralism need not result in some morally deprived, state-centric approach to global politics. It is impossible to do full justice to his work here, but two mutually reinforcing ideas appear to be key for unlocking the idea of a pluralist conception of jus cogens: the possibility of a pluralist world society; and the ethical desirability of human diversity. In what follows, I will sketch out both ideas in a little more detail, arguing that they create a normative logic which leads to a conceptualization of ethos and universal norms quite different from the one traditionally associated with jus cogens.
Williams (Reference Williams2005, 24) sees the classic pluralist focus on static notions of borders and sovereign space as the central obstacle to envisioning any change at the level of structural principles or normative orientation in international society. The first step in breaking the impasse in pluralist debates about progress is thus to clear up the relationship between territoriality and diversity in international relations:
It is not that territorialisation engenders diversity or has in some sense become prior to it. Instead, diversity has been corralled into a territorial form as part of the means for dealing with the special problems and circumstances that come with the constitution of international relations (…)’ (Williams Reference Williams2005, 29).
Once diversity is de-territorialized it becomes an essential feature of international life – something that can well be accommodated by the kind of progressive political space traditionally associated with cosmopolitan institutions. The crucial difference is that the institutional framework of this sort of space is not designed towards agreement or resolution, but about learning from and comprehending those that live outside our bounded community.
The idea that diversity can generate a global public space where expressions of interest and identity are not merely state based opens the door for thinking about a pluralist conception of community ethos, but the door is kept more permanently opened by Williams’ (Reference Williams2015) normative commitment to the ethical desirability of human plurality. Drawing on the political philosophy of Hannah Arendt and the sociology of Gerald Delanty, he argues that international society as a pluralist association of human communities is normatively significant, because there is something inherently desirable about preserving the plural nature of human life. The fact that the world is composed of ‘diverse human social systems with different normative positions arising from different understandings of a whole range of ethical questions’, Williams argues, is ‘a normatively desirable state of affairs’ (Reference Williams2015, 37).
Peremptory norms in a pluralist international society: ethics, function, and practice
Taking a normative commitment to diversity in human life as a starting point for thinking about common identity and ethos engenders an alternative image of jus cogens. A pluralistic international society is a site of the toleration of difference, of comprehension and learning from others, and of restatement of the authenticity of plurality in global life. The critical question is, of course, how such an international society can generate substantive moral agreements. William’s (Reference Williams2015, 155–77) discussions of human security and distributive justice seem to suggest that a normative commitment to diversity does admit the existence of globally shared standards and practices. But how an association of multiple human communities predicated on the enactment of difference establishes universal, non-derogable norms that transcend space, context, and time without requiring a resolution of competing ethical schemas and source stories is not clear. If there is no durable common conception of identity, purpose, and interest, the ground to generate norms that protect the international community as whole seems to be lacking. Does the problem of jus cogens push pluralism beyond its theoretical boundaries?
Perhaps this issue can be cast in another way, by asking: What are the most ethically desirable relations between diverse human communities which find themselves entangled in an international society marked by the excitements and tensions of difference relations? A response to this, I wish to suggest, begins by charting a different perspective on the nature of common ethos and collective identity. As the inconsistent responses to humanitarian emergencies in Rwanda, Kosovo, Darfur, Libya, Syria, and countless other places show, the logic by which international society’s common interest and purpose is established does not proceed from some universal foundations through deliberation about its realization to necessary conclusions about specific political actions. To treat the idea of ‘community’, as it is typically done in IR, as a site at which the society of states shares the same identity or at which debate and agreement will reveal one set of common values may thus not be the best way of thinking about international society’s collective ideals and interests. The standards of ideological unity and homogeneity which traditional natural law conceptions of jus cogens presuppose, and which cosmopolitan accounts of universal rights and obligations wish to fulfil, ignore the ambiguity and contingency of identity.
Accepting that identity is contingent, ambiguous, and can be reconstituted leads to a conception of society that establishes bounds between its members via a common ethos of respect.Footnote 20 Connolly’s (Reference Connolly2008) concept of ‘agonistic democracy’ is interesting here, because of the way in which it carves out a political space in which relations are based on adversarial respect rather than value consensus. Connolly’s political theory is rich and complex, and efforts to explore his thought in ways that can help to study problems in IR remain limited, although potentially very interesting (e.g. Tambakaki Reference Tambakaki2009, Reference Tambakaki2012). What matters most to my purpose about his thinking is the notion of ‘agonistic respect’. A social site marked by agonistic respect, Connolly holds, ‘allows people to honour different final sources, to cultivate reciprocal respect across difference, and to negotiate larger assemblages to set general policies’ (Reference Connolly2008, 142). This argument is presented in terms that insert care for human dignity into the relationships between diverse, interlocking, and contending constituencies without imposing a single identity (Connolly Reference Connolly1991, x). I take human dignity as a central element of a pluralist version of international society, because it is not part and parcel of a specific identity, but the condition under which human communities can develop their specific characteristics (Dillon Reference Dillon2015). To be sure, agonistic respect does not exhaust the global social space, but it can be a crucial logic through which a common ethos among diverse agents is established.
How does this help? In the first place, a conception of international society built on agonistic respect moves away from the pursuit of a single, substantive vision, or purpose. Instead, it becomes a place where common ethos is an expression of cultivating a specific culture of interaction, rather than a place of resolution of difference. This culture is rooted in the recognition that different human communities constituted by different identities and operating with different ethical schemas and normative visions face the same issues, struggles, and problems (e.g. Connolly 2008). Respecting the different ways in which others frame, debate and resolve those issues, struggles and problems, and acknowledging self-limits in relation to one’s own solutions and practices, are the virtues that establish connections across differences. Though ‘respect’ is still an underexplored concept in IR, Wolf’s (Reference Wolf2011) first theoretical cut at the issue reinforces the argument that ‘respect’ is central for developing closer social ties among states. Crucially, Wolf (Reference Wolf2011, 106) sees ample ground to assume that respect can foster international co-operation, precisely because of the way conformation of one’s self-ascribed value and characteristics nurtures trust, open debate, and mutual identification.
A normative commitment to diversity and reciprocal respect makes unpredictability a central feature of world politics, and indeterminacy an integral part of normative order. For pluralists, this is a desirable scenario, because it presumes that human communities engage and behave in a social way on their own terms. There are, however, limits to tolerable diversity and the restatement and enactment of difference. Even a more conservative voice like Connelly (Reference Connolly2008, 144–45), whose view on ethical standards and normative judgements is far more contextual than Williams’, recognizes that in order for diversity to flourish, some kind of limits need to be set. When terrorist groups, dictators, or religious extremists seek to impose and universalize their fundamental beliefs in pursuit of their visions, principles, and institutions, a threat is posed to the ethos of respect. Diversity, to borrow Williams’ (Reference Williams2005, 32) phrase, ‘needs both protection and limitation’ – and it is here where jus cogens play its role: a pluralist international society must develop some universally accepted constitutional norms that that are able to operate as a constraint on violently intolerant members of international society that deny people to practice their own normative and social visions. Jus cogens is arguably among the principal international institution of this sort, because of the way in which it seeks to set fundamental and definitive limits to the way in which political communities can realize their pluralistic, self-directed freedom.
It is beyond the scope of this article provide a comprehensive list of current peremptory norms, or to offer any concrete methodological guidelines for their identification. At the most general level, I have suggested that an analysis of international society’s constitutional values and principles is analytically prior to the development of criteria for identification, because the jus cogens status of a norm is determined by the normative character of international society – rather than simply being expressions of a particular class of liberal human rights norms that have spread across international society after World War II. From the pluralist perspective advanced here, peremptory norms are normatively superior because they are essential instruments for protecting the diversity, the principles of tolerance and respect, enabling rather than constraining the members of international society. They provide the conditions for preserving, restating, and enacting the diversity of human life, not by promoting specific types of behaviour, but by preventing actions that would disrupt the society’s plural freedom.
My intuition is that such a reading of jus cogens would yield a more limited inventory than its solidarist counterpart. The right to self-determination is clearly a constitutional norm in the pluralist sense, because of the way in which establishes a community’s claim to develop and pursue its own political structures and ethical schemas. The peremptory status of the prohibition of slavery and genocide, and the non-use of force can also be ‘relatively’ easy understood in pluralist terms, for they outlaw behaviour that is, if not deadly, destructive of agent’s distinct identities and social environment. The more controversial cases, of course, are those norms that seem to be exclusive expressions of cosmopolitan ideas about harm and inhumane treatments, most notably the prohibition of torture. This is not to say that societal relations grounded in agonistic respect cannot generate any highly durable, robust (moral) agreement about the peremptory status of certain individual rights that transcends context, only that such an account implies a different logic through which they are created and sustained. Rather than being constructed as a top-down exercise, the universal character of human rights is predicated on a hard core of similarities in ethical standards and social practices coupled with a common ethos of respect.Footnote 21
Because there is no single, eternal logic that brings about foundational claims about the interests and moral vision of international society as a whole, the rank of a norm is, and ought to be, constructed through social process in which contestation, reappraisal, and reinterpretation are likely to play a key role. This explains, and perhaps even supports, the deliberate ‘emptiness’ of the jus cogens’ provision in the VCLT. The specific content and rank of a norm is a product of social practice, not dictate, thereby remaining contextual, circumstantial, and ultimately amendable. Different international societies have developed different criteria for membership and rightful behaviour, and even the most fundamental and durable Westphalian norms – sovereignty and non-intervention – have undergone substantial transformations. Lawyers sometimes seem to be puzzled by the degree of contestation surrounding peremptory rules, most notably because of the way in which such behaviour undermines their non-derogable character. This issue has been particularly salient in the context of George W. Bush’s post 9/11 efforts to reduce the scope of what is meant by torture. As Foot writes ‘Why, (…) given the rhetorical, moral and legal status of this prohibition, is torture being debated, contemplated and even resurrected as an unsavoury and allegedly necessary course of action?’ (Reference Foot2006, 132). For constructivists, however, contestation is an integral part of every norm’s lifecycle, no matter how fundamental their status. Because the social recognition of norms, including legal norms, evolve and persist through interaction in contexts, their meanings and significance ultimately remain dynamic by definition (Wiener Reference Wiener2009, 179–80). This holds particularly true for beyond-the-state contexts, where acceptance of and compliance with rules depend decisively on shared recognition rather than on their formal validity (Wiener and Puetter Reference Wiener and Puetter2009, 4). In fact, as Reus-Smit’s (Reference Reus-Smit1997) comparative analysis of international systems shows, it is not uncommon for states to contest even the most basic constitutional rules and principles of a historical era.
Conclusion
Proceeding from the assumption that jus cogens is part of an interrelated, institutionally integrated normative framework rather than a centralized system of rules and authority, I have argued that we can only fully understand the existence, legitimacy, and function of jus cogens through social theory, and specifically by reference to the shared values and purposes of international society. The conception of jus cogens I have pursued, however, is only a first attempt in producing a social theory of peremptory norms. Above all, such a theory would have to provide further clarification as to the nature of a sociological account of jus cogens in relation to the theory and practice of international law. Which forms of legal normativity (e.g. treaty, custom, or even general principles) do a better job at institutionalizing the constitutional functions of peremptory norms? If jus cogens is constructed and sustained through social interaction, providing a social-constitutive role in international society, what difference does its inclusion into international law make? As the article indicated, constructivist accounts of law are likely to open up critical space for inquiry here, because of the way in which they help to disentangle the complex conceptual relationship between legal normativity and social forms of practice.
Another interesting question concerns the normative content of peremptory law: How can sovereignty norms and human rights be reconciled in a coherent theory of jus cogens? This is an instance where some research on variations in and interactions between solidarist and pluralist logics might be helpful. It seems that the most significant normative clash within the current global order is between the inherited norms of the Westphalian state system, which privilege particularistic values and principles, and more recently established norms seeking to protect universally shared values and principles (Brown Reference Brown2002, 76). The debate about jus cogens sits at the heart of this problem in that any solution has to organize these competing norms in a predictable and systematic manner. The current international society has found no solution yet, and it seems that its members simply do not know how to deal with the complex normative environment that has emerged since 1945. Both fundamental human rights norms such as the prohibition of genocide as well as Westphalian norms such as the non-use of force and the right of self-determination are said to have peremptory status – and international political practice in cases such as Kosovo, Libya, and Syria demonstrates that there is anything but a clear consensus around the ranking of those norms.
The article only broached some of these issues. Working out the relationship between the social, ethical, and legal dimension of jus cogens should be a fruitful task for both IR theorist and international lawyers, touching on some of the most interesting axes of interdisciplinary scholarship on norms and normative order in international relations.
Acknowledgements
The author would like to thank the anonymous reviewers, the editors of IT, and Matthew Weinert and John Williams for their incisive comments on earlier versions of this article.
