Survey Article: The Legitimacy of International Courts*

States are free, yet everywhere live under international courts. Sovereign states are no longer in a state of nature without arbitrators among them on matters ranging from territorial disputes and human rights to international crimes, cross-border trade, and investment. The core task of these international courts and tribunals (ICs) is to adjudicate disputes through interpretation and application of international law by legal methods. Their judicial adjudication may also contribute indirectly to a range of tasks—to prevent war, protect human rights and foreign direct investments, harmonize international law, but also to usurp law-making power or perpetuate global injustice and domination. As ICs proliferate and gain power across ever more domains, they become targets of a bewildering range of resistance.2 Criticisms often invoke ‘legitimacy’. Some question ICs’ origins—querying, for instance, why developing states are forced to accept investment tribunals that privilege foreign investors.3 Their processes are criticized—for example, when UK Brexiteers challenge the legality of treaty interpretations by the Court of Justice of the European Union (CJEU).4 The interpretations by the Appellate Body of the World Trade Organization (WTO AB) face criticism both for being too expansive5 and for not protecting the environment even more.6 ICs’ legitimacy may also suffer from their outputs, be it the backlog of cases of the European Court of Human Rights (ECtHR)7 or the too few cases decided on their merits by the International Tribunal for the Law of the Sea (ITLOS).8 Such concerns and taxonomies lack an overarching account. Some may therefore dismiss legitimacy criticisms as emotivist, mislabelled, confused, or mere manipulation.9 Others may regard such challenges as category mistakes, since legitimacy theories usually address inescapable state power over individuals. In contrast, IC jurisdiction requires state consent and seldom entails sanctions in a strict sense.10 A more charitable reconstruction of these criticisms recasts them as questioning the legitimate authority of ICs. Why and when are ICs justified in claiming that others should defer to their judgments and interpretations? ICs have several ‘deference constituencies’ beyond states: they claim deference from investors, individuals, international organizations, and other ICs.11 But the ICs’ legitimate authority over states is central, since international law is largely based on state consent—so ICs are, in some sense, optional for them. Furthermore, ICs lack independent enforcement powers and must rely on states’ compliance. How states regard an IC’s authority is therefore crucial to induce states to consent to it, convince parties to defer to interpretations and judgments, and to keep them from exiting its jurisdiction—or even closing the IC down.12 What reasons might a state have to defer to an IC’s judgment or interpretation, even when the state regards it as mistaken, and even when it conflicts with the interests and objectives of government? This overview draws on Raz's account of legitimate authority that addresses similar puzzles: how to justify obedience to commands somewhat independent of their content, and that preempt or exclude some of the subject’s other reasons for action.13 This account may not be what critics have in mind, nor does the argument schema provide substantive arguments or seek to show that all such criticisms are correct.14 The aims are, rather, to make many such criticisms comprehensible as legitimacy concerns, to provide a rationale for popular taxonomies of legitimacy criticisms, and to indicate which premises and arguments are required for such criticisms to be correct. Section I sketches the multiple tasks of ICs, in complex interdependence with other actors. Section II addresses some aspects of the relation between the normative legitimacy of ICs and descriptive legitimacy, and actors’ beliefs therein. Section III shows how a wide range of legitimacy challenges concern ways ICs fail to carry out their tasks. On this account, an IC enjoys legitimate authority over a state when it enables the state to better act as it has appropriate reasons to—be it to increase international trade and direct foreign investment, or to promote human rights at home and abroad. The various tasks of ICs may enable the state in several different ways.15 The IC may be wiser than the state; have a steadier will less subject to bias or weakness; it may help the state avoid self-defeating strategies; reduce its decision-making costs; or it may be better positioned, for example to overcome coordination problems.16 On this account, an IC may be a legitimate authority for some, but not all, constituencies, even if its treaty fails to secure full justice, and even if it issues some bad judgments, as long as it enables that subject to act somewhat better.17 States have tasked ICs to adjudicate disputes by issuing impartial judgments based on international law by legal methods.18 In doing this core ‘micro-level’ task, ICs also perform other ‘meso-level’ tasks.19 First, in order to adjudicate, ICs must often specify and interpret treaties to fit the particular circumstances.20 ICs in effect develop and often set precedents with implications beyond the particular dispute. Public justifications and dissents further stabilize and specify expectations.21 This task violates standard views about the courts resolving disputes based on pre-existing rules,22 and trespasses on the traditional separation of powers. This task requires constituencies to treat the IC’s development of international law as authoritative reasons for action. In adjudicating, ICs also perform further tasks. States have established many ICs in the belief that such judicial dispute resolution will promote broader, longer-term meso-level tasks—even avoiding war.23 States have created regional human rights courts to promote and protect human rights.24 The International Criminal Court (ICC) and other criminal tribunals were set up inter alia to deter atrocities and to end impunity for international crimes.25 The WTO AB and investment tribunals were meant to encourage international trade and direct investment.26 ICs would be better positioned and provide a steadier will for states. ICs can also provide ‘legitimation’, when they review an actor, to assure third parties that it is trustworthy.27 States use the prospect of future impartial adjudication by ICs to send ‘costly signals’ to their own citizens, other states, investors, or trading partners.28 An IC can also help a government reduce the risk that its successors will violate a treaty, tying their hands beyond what domestic constitutions can do.29 This has led some states to ratify the European Convention on Human Rights (ECHR),30 and is arguably one of several tasks of the WTO,31 the arbitration panels under international investment agreements,32 and the ICC.33 ICs are better positioned than states themselves to provide such assurance. ICs may also promote general rule following and induce enforcement by reducing the likelihood of free riding. They can secure ‘collective action over some set of policies among a set of states’,34 both by shifting incentives and by assuring ‘contingent compliers’ who will comply only if others do so. ICs can fulfil these tasks even without sanctions, when they settle disputes about compliance and provide public information about norm violations.35 This may trigger third-party sanctions and other ‘outcasting’ reactions,36 such as when the WTO AB authorizes the winning state to impose otherwise prohibited tariffs on the loser.37 These tasks require public knowledge that the state will regard the IC’s judgments as authoritative, displacing some of the state’s own reasons for action. Many ICs also perform ‘macro-level’ tasks through their judicial interpretation and adjudication. States do not always foresee the need for tasks carried out by ICs, such as harmonizing different treaties by ‘systematic interpretation’, ‘judicializing’ international relations, or strengthening the ‘international rule of law’ and ‘constitutionalizing’ parts of it. ICs also delineate the scope of states’ sovereignty when they interpret international law. Whether ICs are effective in such tasks and whether these objectives are laudable is contested,38 but in the heat of treaty negotiations they are arguably better placed than states with less systemic perspectives. To assess ICs’ performance of such tasks, and hence their legitimacy, we must consider that they interact in complex interdependence with other actors, and recognize that each IC may perform several of these tasks simultaneously, and for various constituencies. This clutters the landscape, helps explain the bewildering range of criticisms, and hinders any overall assessment of legitimacy. This brief overview illustrates that the various tasks of ICs often rely on their core role of impartial dispute resolution by the use of legal methods and sources. This sets them apart from other ways to address disputes or coordinate and stabilize expectations, such as bargaining, war, case-by-case mediation based on discretion or considerations of equity or fairness,39 good offices, or conciliation. Standards of legality and rule-of-law values seem necessary for ICs to carry out their core task,40 yet may sometimes stand in tension with the other tasks.41 The role of any IC is limited; its effects arise in interaction with other actors who are more or less willing and able to defer to its judgments and interpretations. The tasks of the IC are to enable states, not to coerce them. ICs enjoy varying legal powers over states and their other constituencies, and serve different subsidiary roles. The WTO AB may replace domestic dispute-resolution and states must its judgments or risk by other states. The and should domestic The and should domestic an IC may arguably sometimes some of its tasks even if states not to defer to its judgments and interpretations. The between and legitimacy and their for compliance merits On the account, descriptive legitimacy to actors’ beliefs about the legitimate authority of the Such beliefs about normative legitimacy sometimes to have of be not to such but it is the IC requires actors to do what they would have But actors’ belief in the legitimate authority of an IC may contribute to more that the judgment them a to act in which them somewhat more to act belief in the legitimate authority of an IC can to secure deference to it even by who a or with a legal This normative may be to the IC being to carry out the tasks ‘international courts will enjoy and be as authoritative only if states and other them as at in the long reasons to defer to the judgments of an as a legitimate may be not to free on or to their human rights and to assure constituencies Such public justifications may be to for and compliance with ICs, necessary for them to perform their tasks and to A between compliance and legitimacy in the complex of an of with an IC’s judgments may beliefs about the IC’s normative legitimacy, or about the actors’ normative ICs often to their descriptive legitimacy by issuing judgments with on all The to its descriptive legitimacy in the of some states, when the to comply with its in of The that the disputes by legal than to the This constituencies’ belief that the legitimate A third is that compliance by some states with an example, to its descriptive its normative legitimacy, states to prevent free on An IC fails in this task if many states to defer to it. In this the IC help any state to the coordination it is no legitimate authority for any of legitimacy of ICs often without any for the of the how and why it set up in Section whether its are appropriate for its tasks, such as disputes by legal methods concerns about the IC’s effects in several These are the ways ICs can fail in their tasks, and hence fail to be legitimate judgments This account can to assess whether such criticisms are to international law, states must consent to any IC challenge both whether state consent should be and whether it is to to are reasons to states who fail to ICs that are and necessary for such to address or to protect human rights and the This account some of these States may often have good to defer to ICs, yet fail to do and they may have several further reasons not to free on who some such criticisms may be and often the question of which might be better than consent to state A yet argument for state consent is of state to and act on of and their a of legitimacy on international The nature of that have to act their is state consent to an IC in general or to a particular arbitration often does not seem free or to normative of consent in other the World to International Many states have nor any to consent to the WTO or to investment treaties this account several reasons to some to state by the treaties that ICs and subject to their This is not to that states’ lack of consent out of international law, such as international law and general of public international consent may avoid or reduce several states have over their own the consent it more that it will and IC judgments The likelihood of general compliance may in each to comply with ICs. consent may also a to as the is that the states do as they To require consent may also somewhat of by more states in treaty states may their to secure or consent by all states may a more of and than the of states even of states may from some treaties and from ICs for trade, and domestic human the treaties are often on some states and citizens, the ICs may be legitimate as they help both and states act in better with their appropriate This is not to that yet other of treaty might more example, in a without states, or by a in a global consent may sometimes also be a for states to on one among several treaty each of which to coordinate for example in of the Such will require state to defer to the even states would have reasons to other These are not reasons for state consent as a for the legitimacy of ICs. is often a and other may also reduce or help coordination A wide range of legitimacy challenges to ICs concern their in a ICs can usually do their tasks only if they perform their core task of impartial legal dispute resolution States and the ICs themselves face complex challenges in the required of international and and must the of the IC from the and the of the in a particular and provide appropriate Some aspects to stand in some is the IC’s performance of its tasks that it a legitimate The core task for ICs is to adjudicate disputes by issuing judgments on the of legal and legal for example, resolving disputes by or They should be to their and legal of treaty interpretation and legal to at impartial must be to do This task requires that the IC is independent of the parties to the and that the are to be impartial in the particular The and among for example disputes or human rights the to assess and the instance, of ICs more independent than arbitration to act more if they be The of the serve one and In order to settle disputes and by legal ICs must be independent of the parties to the and enjoy wide discretion to interpret treaties and make international law. The of the rule not of law, but of who enjoy with too few for arise from the often of many actors’ who and help and by IC may be on their own or as an of states, or ICs’ must be or to that develop the treaty and by legal and are to do states to defer to ICs as better positioned than ICs must be independent from the states disputes they adjudicate, some and from domestic are and are such as state and and of The the range of challenges and of and one for the on of each from a of the state both must the legal of the and The international investment arbitration panels of one by the one by the and a third by or by the This to the effects of judgments beyond the parties to the and concerns about their and with other parts of international Their core task of disputes and treaties by legal methods requires ICs to rely on legal and and comply with various rule-of-law This the legal of and of A criticism is that ICs from of legal and rule of law when they interpret beyond what states In the ICs’ interpretation and even law is arguably by states when they the treaty to treaties usually require states to some by or a treaty for the IC is often to of treaty interpretation by the states, such as the and of the States are also often and to specify treaties to to reduce their own decision-making They it to the IC the that through the will a of international The of ICs may arguably reduce the of state power in this law-making when disputes and when developing the treaty, the IC must the of the arguments on of all This concern on the international of different legal and arguably of and other of the Such may also show that the IC the parties to the dispute as ICs secure such knowledge in different The always the by the state on the the Court of Human Rights such to rule-of-law reduce the risk of and that the their discretion with and such also the effects of judgments and interpretations. These arguably contribute to the ICs’ role in future disputes and and the and legality to and an judicial judicial and judicial it is to at any but not all of these They the with the the and the less to and The account might reduce the of this by the and of and required for international to their core task of issuing impartial judgments based on legal the effects of an as it helps states secure objectives otherwise out of this may the IC’s to states and other deference constituencies reasons to To show how this account helps assess criticisms of the effects of ICs, we may between the IC’s its judgments and its in the of compliance with particular and the of such compliance on the that the legitimacy from its backlog of The fails to adjudicate human rights and hence to prevent future This account and of this criticism states all, the The arguably its task to enable states to fulfil their human rights states fail to The the states which of the to legitimacy does the of substantive cases for challenge its States may not its of dispute adjudication a to This in the core task of may its range of tasks in the treaty further and it may help states avoid disputes if they them its in of The lack of cases is often a challenge for ICs, which may seek to their or themselves as better than dispute the in a for the of investment it may also have to in such with judicial of and How does states’ deference to an IC’s judgments and interpretations its legitimate to some action may require no free ICs can enable states in such by and compliance. These can be ICs have other tasks than to An impartial IC can contribute to law and even if some parties to the dispute comply with the judgment human rights ICs can assure other parties of a state’s even if some states with a human rights judgment may the of the in a complex On the other may challenge the legitimacy of ICs. the task of ICs is to prevent free but several states may be out of and no state may have to defer to the an IC help a state to human rights compliance if many states fail to The IC is no longer better placed than the state to provide and its legitimacy may be at Some of the cases for ICs arise when they must adjudicate to legal yet face states, which may to comply or even from the jurisdiction of the Such cases might be by ICs when they must their since act of by a state that in a may its concerns that full compliance to the for which it created can its Some such laudable objectives are human rights to of international criminal law to justice, promote the international rule of law, or global What if the does not deter or if investment treaties and tribunals do not more foreign direct This account some on the complex of such lack the legitimate authority of ICs. First, states and other deference constituencies have often tasked ICs with often the will not be able to deter and all to justice, and full to and a and to all and challenges when an IC on in a of the and the Court as trade but to human rights and Such may be as the IC helps states better protect and promote the interests of individuals. the of tasks to which of instance, even the to have some it will deference constituencies for to secure other objectives tasks for an IC the of and of to help deference act may also challenge how the IC its discretion to multiple example, whether the Court or the appropriate to human rights to even if objectives stand in some the IC may enable states to act somewhat A challenge when the IC’s of dispute resolution is a for the it does not perform the task that states and may not be legitimate it other tasks. for such is the of be it states or other concerns that investment treaties may fail to contribute to states’ of foreign direct A third concern is effects of ICs. The account that an IC may not be legitimate even it states’ objectives as they of may Some critics that states have tasked ICs with example, that the WTO AB the global to the of or that trade or investment treaties and ICs some states’ Some ICs may enjoy descriptive ICs may also be if they have other nor International law is often as is that are no ways to conflicts among treaties and ICs, for example by all of them to human rights or Some claim that trade ICs prevent domestic from protecting human rights or the environment the of Others claim that international investment arbitration tribunals and the WTO AB international trade or prevent domestic to of global Such criticisms and of the and ICs on complex of the complex interdependence among and challenge for such of concerns which of good reasons to Some of an IC’s tasks, in complex interdependence with other actors, have implications for the of it should interpret and and the we should use to assess it. are at reasons for in normative to on ICs. First, the legal in treaties are largely the of under and only from power not they deference by ICs tasked to and interpret them. these legal must be in ways for application and and by states, ICs, and other actors. instance, ICs may have to assess a state’s claim to enjoy an to a example, to or of Such must be by and all parties may make to or the tasks and interdependence of ICs with other about which normative we should ICs to for example, when treaty normative might to the global legal and example, of be appropriate for some but to ICs’ task of states the appropriate for ICs may have to a need to among states and other constituencies which about substantive of such but which recognize normative reasons to rely on a The normative legitimacy of ICs in on how they perform their several tasks in a But states’ as in treaties are not and ICs may or effects on many appropriate reasons for action. These may beyond treaty to harmonizing and international law, domestic state sovereignty and to states when their scope of Some critics of legitimacy challenges to international law in and to ICs in dismiss such concerns as more than a of as that is only as long as it normative its This overview that such are at can make some of the bewildering of legitimacy challenges to international courts. to interpret and to assess if not all, such concerns draws on account of legitimate which to the tasks and complex interdependence of these international courts. An IC enjoys such legitimate authority when it actors’ to do what they have appropriate reasons to from human rights and international criminal to in global trade Such legitimacy criticisms must be in each by the tasks of that IC the complex legal and On this account, if not all, legitimacy criticisms to question whether the IC such tasks, and whether the IC the appropriate when the tasks Whether such criticisms are and whether any IC legitimate authority over various deference and to be