I. Content-Related Functions

If an emphasis is put on the relationship between law and the social reality it operates in, the first and most inherent function of law comes to mind: Law shapes social reality. In this respect, law is considered as a tool for shaping, framing, and even constructing virtually all areas of human interrelations on the individual and institutional level. This shaping function is at the core of law being a set of norms. All norms—be them legal, moral, religious, or otherwise—inherently contain a normative claim on how reality should look. This claim can be translated into the shaping function of law. Put in temporal terms, law enables a society to shape its future.Footnote ¹² From the perspective of social science, one could consider an explicit shaping function to be the main function of all norms; norms are created to solve a social problem.Footnote ¹³ For some, these social problems arise as a result of social change—thus, law should ultimately be seen as a response to social change.Footnote ¹⁴ But even without going that far, law has the potential to broadly influence the substance of social and political relations.

Legal norms have the effect of shaping reality in all phases of their being. In the process of norm-creation, they force political actors to reach a compromise as to what the specific content of a norm should be. In this context, they function as a medium for communicating intentions.Footnote ¹⁵ When the existing norm is applied, it frames the behavior of the addressees in a specific way. It singles out a certain possibility among the many possible ways to behave—making it factually harder to choose one of the other possibilities.Footnote ¹⁶ Thus, law can contribute to securing desirable behavior and preventing undesirable behavior.Footnote ¹⁷ At the same time, it can also contribute to settling disputes.Footnote ¹⁸ When an act of non-compliance is sanctioned, it creates a consequence for the law-violating behavior, a consequence that would not have existed without the legal norm. Additionally, non-compliance leads to an engagement with the norm and forces the addressee into a position to either reach a goal through the norm or despite of the norm.Footnote ¹⁹ The reality-shaping function of law can thus be seen as a hybrid of an indirect and direct function of law. The former refers to the application of law and the latter to attitudes and other modes of behavior which are not obedience to law or its application.Footnote ²⁰ The effect of law singling out specific possibilities and shaping reality in this way can be observed through both direct and indirect implications of legal norms.

Law can also have the function of constructing and securing values. Although, strictly speaking, this function could be included in the shaping function, it has an additional thrust. It can strengthen the respect given to certain moral values.Footnote ²¹ This goes beyond a narrow understanding of a value-related function of law, which only sees law as implementing the community’s valuesFootnote ²² or expressing them.Footnote ²³ In the latter reading, law has a mere executive function. It is seen as taking up pre-existing values and adding a layer of practicality to it. This narrow understanding, however, does not take into account that law can shape, influence, and construct the content of values. It can do this by putting them in a specific legal framework, thereby defining their features, setting limits to them, putting them into a broader context, and relating them to other values. By doing so, law has a normative effect that transcends its execution. Additionally, law also acts as a tool that stabilizes and secures values. Accordingly, law does not limit itself to presupposing independently existing values. Rather, it guarantees the continuity and persistence of the values that are integrated in its legal framework.

For some, this potential value-related function of law translates on the specific social level into a “moral aim of law.”Footnote ²⁴ Like other sets of norms, law provides a standard against which human conduct is evaluated; it provides “standards of criticism of such conduct.”Footnote ²⁵ In doing so, law creates a yardstick comparable to strictly speaking moral principles, leading to a rapprochement of natural law approaches and positivism.Footnote ²⁶ Some even go further to understand law as aiming not just at criticizing, but also at correcting the moral problems and moral defects of other forms of social ordering.Footnote ²⁷ Such a correctional approach comes with the inherent normative claim that law always induces moral improvement, or even that it always enacts the common interest of society as a whole.Footnote ²⁸ A general orientation towards community interests in some legal orders, however, should not be equated with the moral standard that all legal norms always serve a morally good purpose.Footnote ²⁹ Accordingly—and in order to capture a broader variety of approaches—this Article uses the term of law shaping reality.

The potential value-related function of law is the most prominent expression of another, more general function of law, which relates to norms as a stabilizer of expectations.Footnote ³⁰ Norms can lay down expectations in the formal and binding form of law and thus establish a solid basis for expectations and their legitimacy. Human rights provisions are a telling example in this regard. They put expectations regarding political, social, and other guaranties into the legal category of rights. More than just laying down existing expectations, norms can even create and develop new expectations. The normative approach to the value-related function of law can thus be very idealistic. Nonetheless, this of course entails the risk of belying the expectations. Inversely, if law normatively aims at developing realistic expectations, not being too far removed from the existing social reality is a requirement. Also, the legal form makes it more visible when expectations are belied.Footnote ³¹ For law in general, this can be especially problematic with regard to expectations created by legal norms themselves. In this case, the specific (social) expectations on a certain subject matter are linked to a general expectation in law as a concept.

II. System-Related Functions

Whereas, at least in theory, every individual legal norm can fulfill the described content-related functions, this is not the case concerning the system-related functions of law. The latter arise only from legal norms acting as a group. Although it is a normative question to what extent this is emphasized as a function, the effect of system-creation is inherent to law. It is one of the main effects of the coexistence and interrelation of legal norms. Legal norms both create orderFootnote ³² and—different from some other sets of (non-legal) norms—depend on order.Footnote ³³ As a consequence, it is impossible to understand an individual legal norm without also understanding other legal norms at the same time.Footnote ³⁴ This does not mean that all legal norms would relate to each other, or that the formed order includes all existing norms. Rather, groups of norms create an order to the extent that they are interconnected. They do not necessarily relate in an ordered manner to other groups of norms. Inconsistencies exist. Nonetheless, law is indeed characterized by a multitude of interrelations between legal norms, which cause the interacting legal norms to form a structured entity. In this case, individual legal norms transcend themselves, creating a structure that is more than its elements. At the same time, legal norms and the order that they form enable law to regulate itself—law specifies procedures for making changes to it and regulates bodies to apply it.Footnote ³⁵

The effect of system-creation goes beyond the norms as analytical objects. Law can also be seen as a system of legal relations between legal subjects.Footnote ³⁶ By being subjected to a set of norms, the addressees become interconnected as a normative collective—a group of addressees of legal norms. Consequently, law has an integrative effect. This can become a main function of legal norms when law is understood as enabling certain actors to prove group loyalties and create group identities.Footnote ³⁷ The integrative function is emphasized when law is explicitly used to harmonize legal standards applicable to a group of addressees. Legal harmonization is both a tool to shape reality and a strong element of system-creation, going beyond structures but also orienting content.Footnote ³⁸ Ultimately, norms and the unifying standards set by them can promote social integration.Footnote ³⁹

Yet creating a collective is not only an effect and potential function of specific legal norms. Indeed, law as a concept also presupposes a collectivization of the addressees with regard to their trust in this very concept.Footnote ⁴⁰ Law presupposes the trust or belief of every addressee that every other addressee trusts or believes in law. Law is a common idea which can materialize only if the idea is shared by everybody. On this basis, law functions as a conceptual unifier.

With law, as with any system, comes an additional social function. Many theorists are of the view that the function of law is to organize behavior and provide guides to human conduct.Footnote ⁴¹ This enables society or group members to cooperate and solve coordination problems.Footnote ⁴² A key aspect of the system-related function of law is thus to create social order by providing a guiding structure for individual and collective actors.Footnote ⁴³ This could also be referred to as a coordinative function of law.Footnote ⁴⁴ With the coordination of individual behavior comes the structuring of society as a system. When law structures society as a system, it fulfills a function of system-creation on the social level. This complements the above-mentioned system-creation on the level of the legal norms.

Another aspect of the potential system-related functions of law links law to politics. Law can have, and can be given, the effect of constitutionalization—understood as a system-creation on the political level. Within the framework of the functions of law, the term constitutionalization as it is used here describes the fact that a political entity is based on, and depends upon, law. As a result, the entity is considered first and foremost to be a legal construction and is only secondarily considered a political construction. Whereas this is debatable for the political entity of a State, it can be witnessed, by way of example, in the form of the European Union. The EU has been mainly perceived as a creation of law, with its legal nature dominating its political (and economic) aspects.Footnote ⁴⁵ That law is capable of this far-reaching effect is due to the combination of the extensive power-related, content-related, and system-related functions that law can have. They cause law to be “the quintessential institution for creating other institutions.”Footnote ⁴⁶ This mirrors the institutional nature of law.Footnote ⁴⁷

III. Power-Related Functions

The power-related functions look at the relationship between law and politics from two opposing sides, taking into account that law and politics can be “either in agreement or in opposition.”Footnote ⁴⁸ The first perspective in this regard concerns the restriction of power. The power-limiting function of law is one of its most normative functions. Law can set limits to actions of the State and of the individuals belonging to a society; it can set limits to politics.Footnote ⁴⁹ In particular, law in its public dimension channels and organizes power.Footnote ⁵⁰ In doing so, law restrains contingency and creates certainty. The exercise of powers becomes predictable in so far as actors have to abide by the limits set by law. These limits are of both a procedural and substantive nature. Law gives a procedural framework to the way power is exercised and at the same time, it determines the result of this exercise in terms of content. The rule of law discussion both on the national and international level is closely related to this function,Footnote ⁵¹ as well as the idea of constitution and constitutionalism.Footnote ⁵² If the rule of law is understood in the sense of jurisdictio—as opposed to law as gubernaculum Footnote ⁵³—it requires that law should always be controlled by other law, and that political power should always be bound by clear legal norms which are outside of the reach of the political.Footnote ⁵⁴ In this regard, providing certainty and predictability of the exercise of political power and of its intrusion into the sphere of the individual are important elements of this power-limiting function of law.Footnote ⁵⁵ Also, even if one does not agree that law should allow “predicting official behaviour,” the function of law can nonetheless be seen as providing “a standard of criticism of behaviour, including the behaviour of officials.”Footnote ⁵⁶

This can be supplemented by a normative dimension that is related to the aspect of legitimization. For some, the function of law is to justify the State’s use or withholding of force.Footnote ⁵⁷ This can even be stretched further by declaring this function to be law’s defining feature: Anything that does not perform this justificatory function cannot be counted as law.Footnote ⁵⁸ This approach shifts the understanding of law as a tool for restraining power to law being the source of legitimacy for any exercise of power. This fundamentally effects the perception of the relationship between law and power, insofar as both approaches differ with regard to the primary point of reference—law or power. The orientation of both approaches, however, remains the same: Being the source of legitimacy for the exercise of power represents the ultimate restriction of power.

In fact, it is not only the power of the State or of other institutional organizations that can be regulated and limited by law. A further dimension of limitation is situated on the individual level. Law has been described as “attempt to prevent the individual encroaching on the interests of his fellows….”Footnote ⁵⁹ Individuals and their freedom (e.g. their freedom of contract) are subjected to legal restrictions which are linked to the benefits coming with the provided legal framework.Footnote ⁶⁰ This amounts to limiting the original powers within a society before they have been institutionalized. Of course, this variation of the power-limiting function which concerns the individual is closely related to the institutionalization of power in the form of a State. In this context, an important potential function of law is to make the use of force a monopoly of the community.Footnote ⁶¹ This highlights graphically how the relations within the triad individual-State-law is often perceived:Footnote ⁶² In order to limit the power relations between individuals, power is institutionalized in the form of the State and is exercised by the State through law.Footnote ⁶³

Contrary to an understanding that sees law primarily as a limitation to power in its various forms, the reverse understanding is possible as well. Indeed, law can also be conceived of as a tool to exercise power—and not to restrain it. This perspective on the relationship between law and politics might actually be a historically older and more conventional function of law. Over time, it has found a broad variety of forms, including law being a means of economic exploitation and colonizationFootnote ⁶⁴ or an instrument of the State and of “class struggle” in the perception of communist States.Footnote ⁶⁵ The numerous examples further include the influence of lobbyists on legislative procedures, or the contractual inequality in consumer/business contracts. What is more, law can also be used as a tool to mask the exercise of power. The reason for this is that the idea of juridification of human interrelations comes with a claim of independence of the law, a (formal) decoupling from the political. Hence, law can be at the same time the means for and the disguise of power.Footnote ⁶⁶

Although the potential function of exercising power seems diametrically opposed to the power-limiting function of law, both functions are actually able to coexist—each in a moderate form. Nevertheless, this requires an equally “moderate” understanding of the relationship between law and politics that does not see politics as internal to law in the sense of “law is politics.”Footnote ⁶⁷ If one takes a two-pronged approach, the relationship could be described as follows: It is immanent to law that law is the means of politics in view of its creation and design;Footnote ⁶⁸ yet, at least conceptually, law is or ought to be independent from politics once the law has been created.Footnote ⁶⁹ Put differently, law and politics are “structurally coupled systems. Law is the product of political activity which has been fixed in order to organize … political action.”Footnote ⁷⁰ In its moderate form, the relationship between law and politics is such that particular interests never fully determine the outcome of the lawmaking. Under this premise, a power-limiting and a power-exercising function of law can be combined.

I. Challenges to the Content-Related Functions

For the international and supranational legal sphere, the content related functions of law have been most crucial. The idea of shaping reality through law is at the core of both supranational and—to a less explicit extent—international legal developments. The narrative of integration through law has been the essence of European integration for decades.Footnote ⁷¹ Supranationally, law has been given an integrative and shaping function that goes beyond the function of law in many domestic legal orders. The idea of integration through law is also at the origin of the powerful position of European courts.Footnote ⁷²

Whereas internationally this narrative has never been as explicit as for European law, there has nonetheless been a strong legalization of international relations, especially since the early 1990s.Footnote ⁷³ Analogous to the European terminology, one could speak about internationalization through law—or even globalization through law—to capture this development (a development that qualitatively and quantitatively goes further than the narrative of “peace through law” that emerged more than a century ago). Law has been seen by many as “the best way to make a better world ….”Footnote ⁷⁴ Although international law differs from European law with regard to the level of integration, the prominent role of law is comparable. As a consequence, the expectations in law of the relevant law-creating and law-applying actors and of the addressees are also comparable. This is additionally reflected in the equally prominent role of international courts, giving effect to these expectations.Footnote ⁷⁵ Conceptually, certain readings of the development of international law, for instance the concept of global constitutionalism,Footnote ⁷⁶ express particularly high expectations in the shaping function of international law. More generally, liberal internationalism as a basic approach has been described as reflecting an idealistic vision of what international law can achieve in terms of shaping reality.Footnote ⁷⁷

The shaping function of law is probably the most inherent function, not only of legal norms, but also of norms in general, although their shaping effect can differ. As a result of this inherent character, the different kinds of norms existing within the international legal space fulfill this function. This includes both hard legal norms as well as norms belonging to the category of soft law. In particular, norms can shape reality by singling out one possibility—which makes realizing other possibilities harder. To show this effect, norms do not need to be hard legal norms with binding obligations. The standards constructed by soft law are sufficient to factually shape the reality of possibilities.Footnote ⁷⁸ In this regard, it can remain open whether soft law standards are qualified as formally recognized legal norms. Being a form of norms tout court, they are in any event able to fulfill the shaping function of norms. Additionally, they can, when fleshing out existing hard law norms, perpetuate the shaping effect of these legal norms.

There are two particularities in the shaping function of international law. First, whereas international law can fulfill a shaping function and have a shaping effect during the processes of law-creation and law-application, this is the case to a lesser extent for the process of enforcement. The enforcement structure on the international level removes at least partially one of the three phases available to law for reality-shaping. International courts and tribunals, as well as the UN Security Council—though to a factually limited extent due to the frequent use of the veto—are the only active mechanisms of enforcement available. Because of this, a significant proportion of the enforcement phase is taken over either by political means used by international actors, or by non-international actors (e.g. domestic courts). Second, the social dimension of the shaping function of both hard and soft international norms, which relates to guiding and structuring human behavior, is partially mediated. The underlying substructure of human behavior addressed by international law is often not directly the behavior of human beings but the behavior of governments acting on behalf of States.Footnote ⁷⁹ Due to the involved group decision-making processes, this mediated link between norm and behavior can complicates the mode of action of reality-shaping. Additionally, mediated and immediate shaping effects coexist. This is, for instance, the case when State-related international law and transnational law aim at shaping similar areas of human behavior.

The potential function of constructing and securing values has also been important for the international legal sphere. Values, although always present in lawmaking, can be accentuated or downplayed. Constructing and securing values becomes an explicit normative function when norms are openly designed not as technical rules, but as legal translations of certain fundamental values. In the previous decades, international law has arguably seen a shift from a system based mostly on State-oriented principles towards a more value-based order, emphasizing the rights of individual persons.Footnote ⁸⁰ Yet this development has come with a risk, especially when values are given a universal effect. It can affect a society negatively if moral norms and values are represented as universal and absolute; it undermines the differentiated nature of the society.Footnote ⁸¹ As a result, when the existing substantive value-diversity is stressed by international actors, this not only undermines the claim about the universality of substantive standards such as international human rights, but also questions the function of constructing and securing values at the international scale altogether.Footnote ⁸² This tendency is reflected in the criticism against international law of promoting western values, human rights imperialism, and general hegemonic tendencies by the western world.Footnote ⁸³ It has also triggered alternative readings of the existing law, as well as the creation of alternative sets of rules and regimes.Footnote ⁸⁴

More generally, it can become problematic when the shaping function of law is approached in an idealistic way. High expectations in the shaping capacity of law can turn out to be excessive. Wherever these expectations are not met, the trust in law as a concept is negatively affected. This concerns specific aspects of law with specific purposes, such as financial stability in European law, or the use of force in international law. Moreover, it affects law in its entirety. If the trust in law’s ability to shape one particular field is compromised, the overall trust in its ability to shape other fields indirectly is compromised as well.

On the supranational level, the expectations in the shaping function of law have been extraordinarily high. The narrative of integration through law has given jurists the prerogative of interpretation for the process of European integration. The manifold crises in the European legal space—the financial crisis, the migration crisis, and the crisis of domestic rule of law standards, among others—have made obvious, however, that law alone cannot always effectively regulate all areas of human behavior. On several occasions, politics needed to find answers without being guided by law. In the recent past, this often happened on an ad hoc basis and outside of the supranational legal structures.Footnote ⁸⁵ European law—and to some extent law in general—is perceived to have disappointed in times of crisis with regard to the effectiveness of its shaping function. Consequently, one can arguably witness a loss of trust.Footnote ⁸⁶ This loss of trust in law, and in its shaping function, has had a severe impact due to the fact that legal integration is the basis of the entire political construction.Footnote ⁸⁷ The narrative of the EU as a “community of law”Footnote ⁸⁸ is fundamentally challenged.

On the international level, high expectations in the shaping function of law have been present, although probably not to the same extent as on the supranational level. In the international sphere, the predominance of politics is much too incorporated in the idea of international relations to have given law the same creative leeway and guiding role as it has happened in the context of European integration. Nonetheless, the perception that international law can successfully shape the major aspects of international and transnational relations has become predominant for a certain period of time, at least from a western perspective on international law. The legalization and considerable multiplication of international treaties in the post-cold-war period bear witness to that. These high expectations have been challenged by recent developments. Conceptual and factual shifts can be seen both as a cause and a symptom of expectations that are perceived to be either disappointed or overplayed. The various examples include: the unilateral use of force in the context of Ukraine or Syria; certain international courts being increasingly criticized by member States, and even faced with withdrawals; and the rise of populist politics that are critical of international law. This has arguably led not only to stagnation in international lawmaking,Footnote ⁸⁹ but maybe even to a crisis of international law in general.Footnote ⁹⁰

Nonetheless, this analysis of how high expectations in the potential shaping function of international law first developed and have later been challenged, does not reflect a comprehensive global view on the issue. From the perspective of many Asian States, the expectations of what law and especially international law can do, and how it can shape reality, have been significantly lower.Footnote ⁹¹ This is reflected in an under-participation and under-representation of many Asian States in international law regimes, as “[c]olonialism, the unequal treaties, and the post-war experience encouraged the perception that international law is of questionable legitimacy, can be used for instrumental purposes and is necessarily selective in its application.”Footnote ⁹² Thus, the expectations of non-western States are often not only lower, but also different. There are, for instance, different views on which particular power relations and the position of which actors should be reflected by international law.Footnote ⁹³ Moreover, whereas States with strong and independent courts might have high expectations in law and consider law to be self-standing with regard to the political sphere, other States traditionally might conceive of law as more densely intertwined with, and an instrument of, politics.Footnote ⁹⁴ Such internal approaches to law might be translated to the international level, although this does not have to be the case. On the global scale, such diverging expectations of the various international actors about what law can and should achieve can be problematic in itself. This is exemplified by the disagreement over whether and to what extent international law should be value-based.

For international law, another aspect can influence how far-reaching the shaping effect of international law can be. The international legal order is characterized by a strong interlinkage between the law-creating, law-applying, and law-enforcing actors. Despite the multiplication of actors, including non-State actors, international law is still to a considerable extent horizontal law. This is the case wherever there is identity of the makers and the subjects of the law – as well as of those who have the supreme authority of interpreting the law.Footnote ⁹⁵ This leads to a predominance of unanimous lawmaking procedures which, in contrast to majoritarian systems, may often allow only for less ambitious regulations. Fulfilling a shaping function thus is difficult for law when the interests of the actors are perceived as increasingly divergent and when certain actors are in stronger positions to assert their interest. For instance, the emergence of “new powers” such as India, China, or Brazil creates new divisions and makes consent-finding more difficult.Footnote ⁹⁶ Tendencies towards a regionalization of international law can be understood as one of the fall back options for international actors in order to shift the shaping function to a different level.Footnote ⁹⁷ In this context, territorial limitation appears to be the trade-off for upholding a broader substantive shaping function by international law.

Another result of the strong interlinkage between the law-creating, law-applying, and law-enforcing actors is that many (hard) international legal norms are—once they are created—fairly inflexible.Footnote ⁹⁸ Despite the possibility of developing existing provisions through their interpretation and thereby accounting for subsequent practice, a modification or development of the existing international law is often difficult when compared to the legislative flexibility of other legal orders.Footnote ⁹⁹ Classical international law has always been relatively static.Footnote ¹⁰⁰ Consequently, it can become a challenge for (hard) international law to fulfill a shaping function, given that adapting the law to changing circumstances—and ultimately to a changing reality—is limited by various procedural and political factors. In order to create a higher alterability of international law,Footnote ¹⁰¹ the international sphere has developed alternative mechanisms, such as an informalization of international regulation. Both States and other international actors use informal instruments to achieve flexibility, potentially combining an informality of the output and of the actors. Although this comes, for instance, for soft law with a trade-off relating to the binding effect of the norms, it fosters the shaping function of international law as it is broadly understood.Footnote ¹⁰²

It can also be more difficult for actors in the international sphere to agree on certain guiding principles for the shaping function of law. For instance, considerations of common good often serve as a guiding principle in domestic legal orders. The concept of common interests is, however, less present on the international level.Footnote ¹⁰³ Although there have been developments towards integrating collective interests into international law,Footnote ¹⁰⁴ individual State interests still seem to be a major factor, and currently even seem to gain traction. This influences the shaping function of international law. Consent-based lawmaking becomes more difficult when there is—despite the rhetoric—no meaningful agreement that lawmaking should generally be guided by considerations of common good, trumping particular interests. Along these lines, some hold the opinion that international law cannot fulfill its “true” functions until there is “an international social system capable of processing conflicting interests and conflicting ideas….”Footnote ¹⁰⁵ Some even go a step further by understanding the orientation towards the common good not only as one aspect of the potential shaping function of law, but also as an essential requirement of the rule of law.Footnote ¹⁰⁶ Even without going that far, at the very least, guiding principles strengthen the shaping function of law. If these guiding principles are less prominent, the potential shaping function can develop with only some difficulty.

Although collective interests as guiding principles might be less pronounced in the context of lawmaking, it seems to play a bigger role when international law is applied. To an extent, international courts and tribunals have attempted to emphasize collective interests as guiding principle. As actors that are neutral vis-à-vis the process of formal law-creation, they are in principle well situated to shape the law from a more holistic point of view because they are less confined by particular interests than States or other actors. This might be one of the reasons for the strong role of some courts in the international sphere, such as the Inter-American Court of Human Rights, or the European Court of Human Rights. Other courts, however, are facing more criticism with regard to a (perceived) particular interests driven approach, such as the International Criminal Court. The existence or non-existence of guiding principles as element of the shaping function of law thus might have a considerable impact on the long-term effectiveness of international adjudication.

II. Challenges to the System-Related Functions

The idea of international law fulfilling a system-related function seems to face more conceptual challenges than the content-related functions. Looking at international law through the lens of the legal order has been criticized by some for being too formalistic or positivistic.Footnote ¹⁰⁷ If one takes this approach, the extent to which international law has system-related effects or functions does not matter. The focus is instead on actors, power structures, and other concerns of that nature. For those who consider the (additional) lens of the legal order to be analytically and normatively useful, however, the question arises as to what extent international law has an ordering effect or function.Footnote ¹⁰⁸

The conventional perception is that international law as a whole has a weak character of order. Traditionally, the characterization of international law as an order was put forward when it came to delimiting international law to external legal bodies, especially to domestic law. The emphasis has been put on the external dimension of the order, and not as much on the internal structure. International law is seen less as an internally structured entity which is formed by the interrelations of its individual norms, and more as a set of individual provisions which do not necessary communicate and depend on each other. From this perspective, it is understood as an “unsystematic plurality of systems or regimes.”Footnote ¹⁰⁹ A conceptual unity of international law is regarded as mere chimera.Footnote ¹¹⁰ Accordingly, international law as a whole is perceived to have a less pronounced effect of system-creation.

This perception has various consequences for the interrelations between international legal norms.Footnote ¹¹¹ One consequence concerns the potential existence of structural principals within international law. If one normatively considers international law to have an overarching function of system-creation, structural principles would be one of the potential instruments fostering such a systematizing effect. Based on the interconnectedness of norms within a group, it is conceptually possible to derive distinct legal principles from the interrelations within this group of norms. For international law, however, such a process would have to overcome a potentially restrictive understanding of the numerus clausus of sources of law.Footnote ¹¹² Tying back every norm to one of the sources listed in Article 38 of the International Court of Justice statute makes it more difficult to argue for overarching structural principles. For example, approaches are criticized which try to create integrative structures of order by developing principles of international administrative law applicable to all international administrative regimes.Footnote ¹¹³

As a result—and combined with the increasing fragmentation of international law,Footnote ¹¹⁴—the ordering function of international law has received a regime-specific orientation. The function of system-creation relates not as much to international law as a whole, but rather to sub-sets of legal norms. Within individual international law regimes such as international criminal law, human rights law, or international trade law, the ordering effect can be strong. Hence, the differentiation of the various international law regimes, sometimes fostered by specific regime-related courts or tribunals, actually strengthens the effect of system-creation on a different scale. Contrary to a conventional reading, the fragmentation of international law can, in this regard, be conceived of as an indicator of the normative ordering function being reinforced.

Inversely, opportunities might arise from the fact that the function of legal system-creation for international law as a “universal whole” is less pronounced. If the inner structures of an order are less strong, the order might be more apt to be open to other groups of legal norms. The external permeability of the order can be potentially greater if the internal structures of interdependence between norms are less tight.Footnote ¹¹⁵ As a consequence, there are, for example, some regimes of international law with closer interactions with domestic law than others including: international organizations law;Footnote ¹¹⁶ human rights law;Footnote ¹¹⁷ international investment law; national security law; or, with regard to the need of many of its norms for domestic implementation, international environmental law.

An aspect of the potential system-related function of law that is challenged on the international level is the self-regulation of law. Law is considered to regulate itself based on rules for norm creation and norm application. Internationally, the self-regulating effect of law faces restraints. International norms about norm creation and norm application do of course exist. For example, many treaties have provisions on amending procedures by the parties to the treaty. There is also the Vienna Convention on the Law of Treaties regulating formation and application of treaty law. Even customary international law is confined by rules on norm creation. Yet these formal means of self-regulation have proven to be less efficient in international law than they are, for instance, in many domestic legal orders, as well as in the supranational context. The prevailing, relatively strict formal rules on law-creation are not considered to be flexible enough to meet the needs of international actors.Footnote ¹¹⁸ Consequently, international law-making has developed to reach beyond its own self-regulatory attempts, increasingly using informal processes which are less self-regulated by law.Footnote ¹¹⁹ The application of international law also seems to be less guided by law itself. Given that hard international law, especially treaty law, tends to be created at a specific point in time without much or any subsequent formal modification,Footnote ¹²⁰ the guidelines for the norm application are limited. The international level is different from the domestic context where legislators regularly can provide a basis for interpretation with every modification made to a statute (and potentially even give explicit reasons for such modifications). As a result, international norm-interpreting actors have more leeway. In some treaty frameworks, expert bodies suggest interpretations of legal obligations that amount to establishing new norms.Footnote ¹²¹ In others, international courts and tribunals become creative in the further development of old rules and their adaptation to changing factual circumstances.Footnote ¹²² This is particularly true for treaties with an intended long-lasting lifespan such as human rights treaties which are even less likely to be subjected to amendments than other conventions. Although such tendencies by international courts and other actors are increasingly criticized,Footnote ¹²³ they are in a sense embedded into the structure of international law that offers fewer possibilities for the law to regulate its own application. Less self-regulation by law expands the range of actors exercising a norm-creating function through interpretation.Footnote ¹²⁴

Further, the legal system-creation as a potential function of international law is challenged with regard to the integrative effect that law can have on its addressees. It is increasingly unclear who is actually addressed and bound by international law. Despite decades of discussion about it, many questions have remained without answer: To what extent, if at all, can individuals be considered subjects of international law; are international organizations bound by human rights standards; are corporations bound by international criminal law; or are non-State actors bound by humanitarian law? The appearance of new actors in the international sphere has broadened not only the spectrum of potential addressees, but also the spectrum of uncertainties. Non-governmental organizations, private armed groups, and quasi-executive agencies installed by international organizations are examples that raise the question for the integrative effect of law: To what extent are the defining boundaries of the group of contemporary international law addressees becoming permeable, broadened, or—more skeptically put—indeterminable?Footnote ¹²⁵

Besides legal system-creation, social system-creation can also be challenged in the international context. Social system-creation relates to the coordinative function of law—law coordinates how to solve problems. For classical international law, this kind of coordination can be difficult in some areas. A considerable amount of the existing problems of international nature are partly or entirely regulated by domestic or transnational law. There are “vast areas of extra-national, non-statal human activity, in particular, vast quantities of economic transactions conducted by industrial, commercial, and financial corporations,” which are not coordinated on the international level.Footnote ¹²⁶ Instead, they are subjected to the “conflicting, overlapping and uncoordinated” domestic legal systems and transnational regimes.Footnote ¹²⁷ Thus, the space for law to fulfill a problem-solving function in these contexts is, so to say, highly competitive. From the perspective of international law, this space is—at least partially—already taken. What is more, the problem solving takes place in different legal orders, including the international one, but with little or no structured coordination between them.Footnote ¹²⁸ This effect is multiplied by the fragmentation of international law itself and the little developed coordination between the different regimes. Accordingly, the transnational and multi-level legal structures challenge the coordinative aspect of the system-related function of law. As a reaction, courts have aimed to provide a coordinative effect through the mechanism of judicial dialogue. Courts, however, are restricted both by their position as organs of a particular legal order and by the limitations of case-based judicial law-making. Thus, it is difficult for them to achieve a comprehensive and balanced coordination of the interplay between different legal spaces. If their coordination is not balanced, there is a risk that other international actors will turn to unilateral considerations because they are dissatisfied with unbalanced coordination.

Finally, international and supranational law can have a major effect in terms of political system-creation. Whereas States are characterized by pre-existing political structures, this is much less the case internationally. Of course, power relations between States exist independent of legal regulation, but they are less institutionalized. Law can potentially provide this institutionalization. Accordingly, political system creation is a possible purpose that is of special relevance for law on the international level. Nonetheless, as the example of the EU shows, a strong emphasis on such a function comes with a risk. If the legal dimension remains the predominant one, institutionalization can lack a political counterweight. The created institution might get into disequilibrium. For the EU, the narrative of a “Union based on law” has been increasingly questioned.Footnote ¹²⁹ This shows that the institutionalizing role of international and supranational law does not have an infinite reach and that the effectiveness of law in this regard can face challenges as well.

III. Challenges to the Power-Related Functions

The power-related functions of international law have been a particular focus in the discussion about international law and its history. As has been highlighted by various approaches in international law scholarship, the potential function of law to serve as a tool for the exercise of power is extensively visible on the international plane.Footnote ¹³⁰ International law leaves ample space for power-relations to determine both the content of legal norms and their application. Many scholars have stressed the political character of international law, conceiving international law as a political project.Footnote ¹³¹ As has been argued, the autonomy of international law from politics and power structures is less pronounced than that of domestic law.Footnote ¹³²

For international law, this function presents a challenge in itself. Power-relations being reflected in and strengthened by international law are considered to call into question the legitimacy of international law. Current developments such as States criticizing, and withdrawing from, international organizations and courts is but one prominent symptom of that discussion. The assessment of how international law can serve as a tool for exercising power, however, shall not be repeated here. This Article does not focus on how the potential functions themselves can present a challenge for international law. Rather, it aims at discussing how the potential functions are challenged. Accordingly, this Section will concentrate on the potential power-limiting function of international law, which raises the question to what extent it can materialize.

Despite its traditionally horizontal, non-hierarchical character, international law can pursue a power-limiting function. A certain power-limiting effect of international law exists that relates to both the power exercised by international actors in the international sphere and the power exercised by domestic actors in the domestic sphere.Footnote ¹³³ The most obvious element limiting the international exercise of power resides in the international norms guiding and confining political power. Every legal norm obliging an addressee to act in a specific way, or to abstain from a certain action, can be understood as a potential limit to individual power. These norms aim at preventing actors to act exclusively in their respective interest. If one follows this premise, all the international legal provisions creating obligations for States and international organizations can have, in principle, a power-limiting effect. The extent to which this potential effect materializes in practice is a different question.Footnote ¹³⁴ Beside this general aspect, some international legal norms contain more explicit restrictions of power, such as the norms on the use of force and the acquisition of territory. Under international law, the use of force as one of the elements of power is considered a monopoly of the community. Guaranteeing peace and stability are part of the key objectives of a number of international law regimes. Furthermore, international law aims at limiting not only the individual power of certain international actors, but also their collective power. An example for that are the jus cogens norms that prevent international actors, even in the event of group consensus, to act in a way that would violate a respective jus cogens norm—unless, of course, the international community of States as a whole composes the consenting group. What is more, the international exercise of power can be limited by elements of the separation of power. One of these elements is the creation of international courts and tribunals.Footnote ¹³⁵ They serve as a framework for the application of international law and can contribute to providing certainty and predictability of the exercise of political power.

International law can also restrain the domestic exercise of power by States. International human rights law is the most prominent field of international law which has a power-limiting function. The various human rights instruments and, where it exists, the related international judicial control aim at confining the exercise of power by States with regard to individuals. In particular, they aim at offering an international layer of confinement in cases where the power-limiting effect of domestic law might be considered insufficient. Here, the interconnection between legal orders and the law’s respective functions becomes apparent; international law can fulfill a power-limiting function that shows its effect not only on the international level, but also on the domestic level.

From a normative perspective, international law can have broad or narrow power-limiting functions. A broad function does, however, encounter challenges. In general, an immediate limit to the exercise of power is created by jurisdictio—legal norms controlling other law and binding political power.Footnote ¹³⁶ What exists internationally in this respect is relatively sparse: It would include jus cogens norms, certain norms contained in the UN Charter, norms in Security Council resolutions, and arguably some norms in human rights law. A fully-fledged hierarchy within the international legal norms does not exist;Footnote ¹³⁷ the effect of norms formally equipped with primacy over other international law norms is limited.Footnote ¹³⁸ Instead, the international legal system relies mostly on the indirect power-limiting effect of the institutional structures established by international legal instruments. In this framework, legal relations and power relations are situated on the same level which, in case of conflict, can cause the latter to superimpose the former. The institutional structures established by law aim at counterbalancing such results and at constituting a functional equivalent to an immediate power restriction. Their practical impact is, however, more contingent than an immediate power-limiting effect would be. This can be problematic when, for instance, the international exercise of power intrudes directly into the sphere of the individual. If there are no adequate institutional guaranties, acts of States and international institutions can lack accountability and the exercise of authority can remain unchecked.Footnote ¹³⁹ In such cases, the power-limiting effect of international law is narrow. From the perspective of other legal orders, a weak power-limiting effect of international law can then be perceived as a shortcoming. It is in these circumstances that other legal orders try to compensate for such a (perceived) shortcoming, be it the European legal order,Footnote ¹⁴⁰ or the domestic legal orders.Footnote ¹⁴¹ In this regard, one legal order can serve as jurisdictio for another order. The “Solange” approach of European and domestic courts are an explicit expression of circumstances when a power-limiting function is exercised by an external legal order.

Another challenge for a broader power-limiting function of international law is the fact that other than in domestic or even European law, there is no consensus as to what the object for such a limitation of power could or should be. As demonstrated by the various attempts in international law scholarship to conceptualize what the exercise of power in the international sphere actually means and what forms it can take,Footnote ¹⁴² power or authority on the international level is even less a monolithic force than it would be domestically. Rather, the exercise of power is complex, multi-layered, and diverse. It emanates from individual States or groups thereof, through international organizations or their agents, in legal or non-legal form, affecting individuals directly or indirectly. Given this plurality of ways to exercise power, the objects of potential limitation are not clearly determined and law thus encounters difficulties in setting limits to all these forms of power.

An additional element of the potential power-limiting function is the certainty and predictability provided by law. With regard to international law, this potential function can face challenges as well. This is in particular due to the aforementioned aspects: Without a sufficient element of control over a determinable set of actors, law cannot provide certainty and predictability to its full effect. Moreover, characteristics such as the voluntarism predominant in the international sphere prevent a general and automatic jurisdiction of international courts and tribunals. Thus, there is no certain judicial control over political power and no certain application of law. This can contribute to creating actual or perceived extra-judicial spaces. Such extra-judicial spaces undermine a potential power-limiting function of law. The non-existence of a system of guaranteed jurisdiction as well as the existing or perceived extra-judicial spaces for certain actions and actors might contribute to other actors questioning existing courts and eluding their jurisdiction. The examples of States rejecting decisions of international courts, tribunals, or arbitral bodiesFootnote ¹⁴³ or withdrawing from their jurisdiction altogether have become numerous.Footnote ¹⁴⁴ International organizations can also be placed—or place themselves—in extra-judicial spaces. This is, for instance, the case regarding the question of their liability relating to private law claims advanced by third parties, such as in tort.Footnote ¹⁴⁵ In general predictability as to whether the exercise of power by these actors can be legally challenged decreases with the multiplication of new actors in the international arena.

For European Union law, the power-limiting function—at least of supranational law—is more strongly emphasized than for classical international law. This is in particular due to the existing hierarchy between primary and secondary law. European primary law provides for legal norms which are outside of the reach of the political actors within the institutionalized structures of the Union. When the Parliament, Commission, and Council exercise their political power through lawmaking, this power is confined by the standards set by the treaties. The respect of these standards is controlled by the Court of Justice of the European Union who has automatic jurisdiction in this regard. Thus, the institutionalized political power within the EU is bound by jurisdictio in the form of European primary law. In addition, the dense intertwinement of Union law and domestic law adds another power-limiting layer.Footnote ¹⁴⁶ Indeed, European and domestic law exercise a power-limiting function together. The domestic constitutional law standards are used as an element of power-limitation based on domestic law.Footnote ¹⁴⁷ This, however, bears risk as well. The power-limiting function of domestic law can be used as a pretext for achieving political aims.Footnote ¹⁴⁸ In such a case, the power-limiting effect would in fact have a power-exercising function. This shows how closely power-limiting and power-exercising functions can be interrelated and how the latter might challenge the former.