A. From Judicial Independence to State Unity

The shift in the underlying theory from judicial independence to state unity is identified by Eduardo Jiménez de Aréchaga writing in 1978:Footnote ⁷

Of more recent relevance is the International Law Commission's Articles on the Responsibility of States for Internationally Wrongful Acts (‘Articles’).Footnote ⁸ It is clear from Article 4 that the conduct of state organs is attributed to the state in an undifferentiated manner.Footnote ⁹ The commentary to the Articles explains that, this approach reflects the treatment of the state ‘as a unity, consistent with its recognition as a single legal person in international law’.Footnote ¹⁰

B. A Dissenting View on Attribution of Judicial Conduct to the State

The separate opinion of Judge Tanaka in the Barcelona Traction caseFootnote ¹¹ goes very much against the tide. This may well be a large part of the explanation for why it is rarely referred to, whether with disapproval or otherwise. However, as the opinion emanates from the International Court of Justice, there is a danger that it could be approached as setting out an uncontested perspective. The following discussion therefore explains why the separate opinion is unconvincing and why the shift in the underlying theory is normatively correct.

This was the only opinion which engaged with the merits of the case which concerned the alleged responsibility of Spain toward Belgium due to various acts and omissions of Spain's judicial organs. Judge Tanaka was able to proceed to the merits as he took a different view from the majority of a preliminary objection joined to the merits.Footnote ¹² When discussing the challenged judicial conduct, Judge Tanaka does not rely on unity of the state considerations. His focus instead on judicial independence results in statements very much at odds with the attribution rules now contained in the Articles. He notes that ‘whether a State incurs responsibility or not depends on the concrete circumstances of each case; in particular, the characteristics of the three kinds of State activities—legislative, administrative and judicial—must be taken into consideration. Mechanical, uniform treatment must be avoided.’Footnote ¹³ Of course the Articles deal with attribution in exactly such a mechanical and uniform manner. Tanaka proceeds to note that:

It is clearly difficult to reconcile Judge Tanaka's views with the Articles and, in any event, a further passage perhaps unintentionally obliterates his views on the importance of judicial independence in the context of state responsibility, and lends weight to the position on attribution described in the Articles.

The passage comes at the end of Judge Tanaka's treatment of the nature of judicial conduct which can, and cannot, amount to a denial of justice. His treatment of this area would be generally accepted by commentators past and present. Judge Tanaka begins by noting that the complaints raised by the Belgian government related to the interpretation of municipal law and involved matters ‘of an extremely complicated and technical nature’.Footnote ¹⁵ The case is therefore disposed of on its merits on the basis that erroneous interpretations of municipal law do not, in themselves, result in a denial of justice. Such ‘issues are of a municipal law nature’Footnote ¹⁶ and were an international tribunal to take up such issues it ‘would turn out to be a “cour de cassation”, the highest court in the municipal law system.’Footnote ¹⁷

Having established that the conduct complained of could not amount to a denial of justice, Judge Tanaka proceeds, implicitly on an obiter basis, to identify the types of decisions which can amount to a denial of justice and, in so doing, introduces a latent contradiction.

What can be questioned here is Judge Tanaka's view of the judicial errors described as ‘exceptionally serious’. On the contrary, a misinterpretation of a rule of international law by a municipal court could be an entirely excusable error when, for example, the meaning of the rule is unsettled at the time of the decision. Judge Tanaka is entirely correct to regard such a mistake as capable of incurring state responsibility. However, in doing so, he undermines his previously expressed views on the dominant role of judicial independence when deciding on state responsibility for judicial conduct. Independence based considerations cannot result in a near complete immunity against state responsibility, other than in the most serious of cases, while also having no limiting effect on state responsibility in the face of understandable and excusable mistakes by judges.

The opinion can also be challenged on somewhat more general grounds. It resonates with the objection in the Köbler case raised most strongly by Austria, France and the United Kingdom that recognizing a principle of state liability for judicial conduct would undermine the independence of the judiciary. The argument is that judicial independence entails that the government has no influence on reasoning and decision making in individual cases.Footnote ¹⁹ At first sight, it is therefore perplexing how the government, having surrendered the decision making to a constitutionally independent institution, can be held to account for the errors of this institution. As Toner comments, the objection (which she proceeds to dismiss) is that ‘[s]tate liability identifies the judiciary too closely with the government and executive.’Footnote ²⁰

This perspective only works as a plausible objection by incorrectly elevating judicial independence to the status of an end in itself. The sounder approach is to regard judicial independence as a means to protect freedom of judicial thought which, in turn, safeguards the sound administration of justice. When this is appreciated, it becomes possible to turn on its head the argument that state liability should be resisted by reason of judicial independence. This is because the possibility of state liability provides a deterrent against executive branch pressure to render decisions which are contrary to international law obligations. This deterrent effect can be thought of as especially important in jurisdictions which favour absolute personal judicial immunity.Footnote ²¹ Knowing that that they cannot be personally liable, judges could be more amenable to government pressure. However, a principle of state liability makes it less likely that governments will attempt to exert malign influence towards non-compliance in the first place. Objections to state liability on independence based grounds therefore lack substance. Indeed, there is a dissonance between the frequency with which independence based concerns are raised and their inability to withstand scrutiny. In contrast, it is perfectly understandable how states can be responsible for judicial mistakes which are contrary to international law if the question of attribution is considered through the lens of the state as a unity.

C. State Unity or Undifferentiated Attribution as a Codification

Despite the Separate Opinion discussed above, there is ample evidence that Article 4 of the Articles is regarded as a codification. Most of the cases involve judicial decisions which reflect and reinforce the position of other state organs. The ICJ Opinion in Difference Relating to Immunity from Legal Process of a Special Rapporteur of the Commission on Human Rights Footnote ²² is illustrative here. Malaysia's failure to provide immunity from legal process granted to experts on mission arose from the executive branch failure to inform the courts of the Secretary General's finding of entitlement to immunity, and the trial court's subsequent failure to treat the matter of Mr Cumaraswamy's immunity as a preliminarily matter to be ‘expeditiously decided in limine litis’—at the start of the procedure. Referring to what was then Article 6 of the Draft Articles on State Responsibility (now Article 4), the Court noted that ‘the conduct of an organ of a State—even an organ independent of the executive power—must be regarded as an act of that State.’Footnote ²³ The same pattern and outcome is evident in Lingens v Austria Footnote ²⁴ decided by the European Court of Human Rights. The case involved Austrian court decisions imposing criminal penalties on the applicant for defamation. The decisions were in harmony with the Austrian Criminal Code and also defended by the government which referred to the need to preserve discretion for judges to prevent political debate protected by freedom of expression from degenerating into personal insult.Footnote ²⁵ Ahead of finding a breach of Article 10, the Court's response was that the margin of appreciation afforded to states to interpret the Convention ‘goes hand in hand with a European supervision, embracing both the legislation and the decisions applying it, even those given by an independent court’.Footnote ²⁶

In addition to these cases, Article 4 has also been applied in an unquestioning manner in a case involving disunity between different state organs; specifically, a case in which the executive branch was actively engaged in seeking the reversal of the offending court decisions. The Brazil – Tyres Footnote ²⁷ case before a WTO panel and the Appellate Body involved an import ban on used tyres found to be a quantitative restriction contrary to GATT Article XI. Under the General Exceptions provided by Article XX, the import ban was provisionally justified as being necessary to protect human health. This left the question of whether the import ban complied with the chapeau of Article XX which prohibits the application of measures in a manner which amounts to ‘arbitrary or unjustifiable discrimination between countries where the same conditions prevail’. The application of the import ban had become incomplete by reason of injunctions granted by Brazilian courts which prevented enforcement of the ban by customs officials. These injunctions had been obtained by firms in Brazil for whom imported used tyres were a cheap source of raw material to be made into retreaded tyres. Both the panel and the Appellate Body considered that the injunctions resulted in unjustifiable discrimination in favour of Brazilian retreaders (since foreign retreaded tyres could not be imported) contrary to the chapeau.

For present purposes, the main feature of case was the effort of the executive branch to seek the removal of the injunctions. The following extract from the panel report was cited with approval by the Appellate Body:

The fact that attribution of the judicial decisions was not presented by Brazil, or analysed by the Appellate Body, as a contentious issue indicates that Article 4 is unequivocally accepted as a codification. This is consistent with the state unity theory which underpins the attribution principle. The theory looks at the state from the outside and asks only whether the challenged conduct is that of a state organ. It does not matter if the internal reality is that the different state organs are in a condition of disunity.

In terms of the normative content of this position, it is also worth thinking through the consequences of what would have happened had there been no chapeau violation based on the non-attribution of the judicial conduct. The executive branch would then have been less motivated to challenge the injunctions through national court proceedings in order to remove the violation. The decision therefore added urgency to the activity of the executive branch as is shown by the arbitration on the reasonable period of time for implementation which followed the Appellate Body ruling.Footnote ²⁹ Attribution of the judicial conduct in this case therefore accelerated both GATT conformity and the protection of human health and the environment. It is surely possible to extrapolate that unconditional attribution enhances the observance of international law in all cases.

D. State Unity or Undifferentiated Attribution and Differentiation between State Organs When Assessing Whether There Is a Violation

As is now evident, it is uncontroversial that the state unity theory results in the attribution of the conduct of all state organs to the state without differentiation. A more difficult question is whether this non-differentiation at the attribution stage also requires or implies non-differentiation at the subsequent stage of deciding whether the conduct complained of amounts to a violation.

The ILC Articles once again provide a useful starting point here in that a clear separation of the two stages is envisaged:

This passage explicitly provides that the matter of attribution has no bearing upon whether the conduct complained of amounts to a violation. A possible inference would be that attribution also has no bearing on the conditions under which different state organs can incur international responsibility. In other words, it is a possible inference that an undifferentiated attribution rule and a differentiated approach to liability can comfortably co-exist.

Contrary to this inference, it is argued that an undifferentiated approach to attribution strongly implies and in practice entails an undifferentiated approach to the conditions under which different state organs incur international responsibility. The most direct evidence for this claim is provided by a feature of European Court of Human Rights (ECtHR) jurisprudence. The ECtHR has held that it need not specify which branch of the state is responsible for a Convention breach—the sole issue being the state's international responsibility.Footnote ³¹ It does not seem to be too much of a leap to suggest that this undifferentiated approach when deciding upon liability, is linked to the same approach when attribution is considered.

As the general international law position is that any breach can incur state responsibility, it can be expected that this position would apply to all state organs. This expectation is evident when international tribunals review national court decisions. The enquiry is whether a breach can be detected, and the indications are that this criterion is applied in the same manner to all state organs.Footnote ³² As Paulsson notes:

E. Conclusions on the International Law Position

The starting point when considering state liability for judicial conduct in international law is now clearly the state unity theory. The theory requires that judicial conduct is unconditionally attributed to the state. It also suggests that the branch of the state from which the conduct emanates is immaterial when addressing the formally separate question of whether the conduct complained of amounts to a breach of an international law obligation. In practice therefore, the conditions under which state responsibility can be incurred are the same for all state organs, as is the application of these conditions.

On the other hand, the state unity theory is entirely neutral as to whether the general state responsibility criteria are based on any breach (international law), or only a sufficiently serious breach (EU law). As indicated, the theory only suggests that the general criteria (whatever they may be) should be applied in the same manner to the judicial branch as other state organs. Therefore, to the extent that there is a tightening of the general criteria in EU law for the judicial branch, this represents something of a suppression of a natural implication of the state unity theory.

A. The Nature of the Judicial Function

What did the ECJ mean when referring to ‘the specific nature of the judicial function’? Since Köbler, this has been elaborated upon by the ECJ in Traghetti del Mediterraneo SpA v Italy Footnote ³⁹ and by the UK courts in Cooper. In Traghetti, the ECJ referred to the ‘very essence of judicial activity’ as being the interpretation of legal provisions in response to ‘divergent or conflicting arguments’.Footnote ⁴⁰ This was echoed by Arden LJ in Cooper:

The emphasized term is crucial for it gives the passage its compatibility with the ECJ's position in Traghetti. The ECJ considered it ‘not inconceivable that a manifest infringement of Community law might be committed precisely in the exercise of such work of interpretation if, for example, the court gives a substantive or procedural rule of Community law a manifestly incorrect meaning, particularly in the light of the relevant case-law of the Court on the subject …’. Footnote ⁴²The sentiment that liability in these circumstances must (however rare) be a legal possibility in Member States was recently reiterated in Commission v Italy. Footnote ⁴³

A query here is whether the ECJ intended to suggest that liability for court decisions should be more exceptional than liability for the acts of other state organs. The passages above describe the process by which the judicial branch might reach a conclusion which is wrong as a matter of EU law. Other state branches might reach the same wrong conclusion via the same process, but a distinction can be conceded. Judges tend to reach wrong conclusions having interpreted provisions of EU law in response to ‘divergent or conflicting arguments’. In contrast, administrative officials sometimes reach wrong conclusions in complete oversight of the EU law position. However, should the process by which a wrong conclusion is reached be of relevance to the prospects for establishing state liability?

It is submitted that process considerations are not directly relevant to the question of whether decisions cross the threshold of being manifestly at odds with EU law. This is because there is a single correct answer to this question, unlike, for example, a decision made by a health board on whether to devote scarce resources to purchase one drug or another. Here, the probity of the choice which is made cannot be separated from the decision-making process and it would clearly be a problem if the interests of one set of patients had been ignored.

In contrast, when deciding whether there is a sufficiently serious breach, the decision-making process is only indirectly relevant for evidential purposes. A process which engages with the EU law position is likely to be useful when determining whether the error was excusable or inexcusable for it might well reveal where, and how, the decision maker committed the error. However, the error is neither excusable nor inexcusable directly by reason of the process. Similarly, it is not possible to conclude from a grossly deficient process whether the decision is manifestly at odds with EU law. Indeed, such a process could fortuitously result in the correct decision.

A possible response is that legal issues which are litigated tend to be more finely balanced than those which are not so that errors in the judicial process are more likely to be excusable than those in administrative decision-making. This argument is persuasive only when the origin of the Köbler liability action is a judicial decision. However, the Köbler case itself originated in the decision of a Minister while the Cooper case originated in a planning decision of a London council. Therefore, in both cases, the question of what was required as a matter of EU law would have been, or ought to have been, considered by an executive/administrative official. This question did not become more difficult when it was brought before a national court of final appeal.

It follows that, for all state branches, if the reach and scope of the EU law norm is unclear at the time of the decision, state liability is unlikely to ensue. On the other hand, if the territory within which discretion or judgment can be exercised has already been constrained by clarifying decisions of the ECJ, state liability becomes more likely. Additionally, if regard to the origin of the challenged decision were to enter this exercise, this could even be depicted as disadvantageous to the judicial branch. A higher level of awareness and understanding of the ECJ's case law can arguably be expected of national courts of final appeal than any other part of the state.

Therefore, it is not clear that the nature of the judicial function provides a rationale for regarding wrong decisions of the judicial branch as a more exceptional basis for state liability than wrong decisions of other state branches. However, as the ECJ noted, regard must also be had to the ‘legitimate requirements of legal certainty’, which may be a stronger basis.

B. Legal Certainty

The need to protect the authority of res judicata Footnote ⁴⁴ was foremost among the reasons presented by Member States for either not recognizing state liability at all, or only subject to restrictive conditions. Austria, for example, seemed to appeal to the public policy dimension of the res judicata principle which identifies the public interest in bringing an end to litigation. It considered that ‘a re-examination of the legal appraisal by a court adjudicating at last instance would be incompatible with the function of such a court since the purpose of its decisions is to bring a dispute to a definitive conclusion.’Footnote ⁴⁵

Both the ECJ and Advocate General Léger discarded this position as an objection to the principle of state liability. In the Advocate General's words ‘the legal authority of a judicial decision—and, as a consequence, res judicata—is applicable only in certain circumstances, where there is a threefold identity—of subject-matter, legal basis and parties—between a dispute already resolved and a subsequent dispute’.Footnote ⁴⁶ The ECJ referred more generally to the ‘purpose’ of the proceedings being compared and the ‘parties’Footnote ⁴⁷ and it can be seen how there is an appreciable difference between the initial judicial review against the decision of the Minister in order to obtain the increment, and the later action for damages against the state.

In dismissing res judicata based concerns as a bar to the possibility of state liability, the ECJ might also have referred to the private justice rationale which accompanies the public policy dimension. This is to prevent an individual from being proceeded against twice for the same cause,Footnote ⁴⁸ or, as Briza notes, the ‘main thrust’ of res judicata is legal certainty for private individuals.Footnote ⁴⁹ The ECJ might therefore have observed that to deny the possibility of state liability would be to protect the finality of judgments for the benefit of the state, rather than individuals. However, even without this point, the ECJ noted that ‘the principle of res judicata does not preclude recognition of the principle of State liability for the decision of a court adjudicating at last instance.’Footnote ⁵⁰

Of course, this conclusion does not mean that legal certainty based concerns are completely immaterial in Köbler liability actions. A judgment will only in strict terms have the force of res judicata in subsequent proceedings when all three of the ‘triple-identity’ criteria are satisfied. However, the related matter of whether the second proceeding compromises legal certainty is a question of degree so that certainty will tend to be significantly compromised when the res judicata criteria come very close to being satisfied.Footnote ⁵¹ While the two national proceedings in Köbler were appreciably different, they were also closely related. In general terms, the question at the heart of both cases related to the EU law compatibility of the Austrian condition for the award of the increment. Like Groussot and Minssen,Footnote ⁵² I would also therefore endorse the assessment of Tridimas that,

In sum, legal certainty based concerns are more convincing than regard for the nature of the judicial function, as a basis for a strict approach towards liability for final appeal-court decisions. Additionally, it is perhaps not far-fetched to suppose that national courts hearing Köbler liability actions are likely to detect and use the permission as long as there is scope for them to do so.

A. Res Judicata Concerns

As discussed in the previous section, res judicata concerns provide a valid reason for a differentiated approach to liability for judicial decisions in EU law. Are these concerns less pronounced in the international law context?

Advocate General Léger's statement of when the res judicata principle is at its strongest can be recalled. This occurs ‘where there is a threefold identity—of subject-matter, legal basis and parties—between a dispute already resolved and a subsequent dispute’. Based on these criteria, it is submitted that the most sensitive point which implicates res judicata in the Köbler scenario is that the challenged final appeal court decision will have (or at least ought to have) considered whether the national measure at issue is consistent with EU law. In the event of a positive answer, the same question is considered for a second time. Significantly, the re-consideration is by a national court, albeit that it may make a reference to the ECJ. This re-consideration creates strong identity of subject matter and also somewhat blurs the division of legal basis since the remedy in both cases will depend on an EU law dimension.

This sequence only carries over to the international law context when certain conditions are present, such as that the state in question has a monist tradition and the Treaty provisions at issue are of an appropriate nature, and sufficiently precise, to be applied directly, or that the Treaty has been incorporated. Absent these conditions, the first occasion on which the consistency of the national measure with international law is considered will be before the international court or tribunal.

Looking at the criterion of ‘identity of parties’, there is continuity in the complainant's identity in Köbler actions. Classically, the state is the complainant in international law matters, as opposed to individuals who may have unsuccessfully sought redress at the national level.Footnote ⁵⁴ This is not always so for there will be continuity, for example, when an investor brings a denial of justice claim before an international tribunal having been dissatisfied with the conduct of a hearing before a national court, and having exhausted local remedies. The process of exhausting local remedies would likely create identity of subject matter since the alleged failure in the administration of justice would be appealed within the domestic system. However, there would not be identity of legal basis since the international tribunal would be the first to hear the claim of alleged breach of the international law delict of denial of justice.

On the other hand, there are situations in which continuity in all three elements could be present in the international law context, thereby strongly implicating res judicata concerns. This can occur in claims relating to the European Convention on Human Rights, by reason of the combination of Article 13 which requires the availability of ‘an effective remedy before a national authority’ for those with an arguable claim that their Convention rights and freedoms have been violated, Article 34 which envisages individual applications to the ECtHR, and Article 35 which first requires the exhaustion of local remedies. Suppose that an individual wishes to challenge conduct of the executive branch which arguably violates the Convention. Using judicial review processes which satisfy Article 13, the highest national court to which the matter can be appealed decides that the executive branch has not violated the Convention. Having thus exhausted local remedies under Article 35, the applicant then relies on Article 34 in order to bring the case before the ECtHR arguing again that the executive branch conduct violates the Convention. Should the ECtHR hear the case, there could well be identity of subject matter, legal basisFootnote ⁵⁵ and parties.

However, there is no evidence that res judicata based concerns are raised in cases which correspond with this scenario, even though they have involved the House of Lords denying alleged Convention violations which were later found to be present by the ECtHR.Footnote ⁵⁶ The strongest explanation is that dispute settlement organs at the international level are considered only to be bound by decisions at the same level, and not also by decisions of national courts.Footnote ⁵⁷ This explanation is generally thought to be a corollary of the triple-identity criteria.Footnote ⁵⁸ The domestic decision is not binding because one or more of these criteria tend not to be fulfilled when the case transitions to the international level. However, the non-binding nature of the domestic decision before the international tribunal surely also has normative force even if the triple-identity criteria are fulfilled. Res judicata concerns ought not to provide a defence to a state whose courts have infringed international law obligations. They are outweighed by the power of the international tribunal to rule on the alleged wrong. The true rationale for the absence of res judicata concerns might therefore rest in the transition from one level of adjudication (national) to another (ECtHR) and a robust conception of state unity at the second level. Here, there is no concession to the branch of the state from which the alleged violation emanates.

The significance of this transition can be reinforced by considering the impact of a change in the noted scenario. The starting point is the same with the highest national court to which the matter can be appealed having confirmed that the executive branch has not violated the Convention. One might then question whether the applicant might once again rely on Article 13 to challenge the substance of the national court judgment as a possible Convention violation, rather than commencing proceedings before the ECtHR. There is presently no definite answer in ECtHR case law on whether Article 13 is generally applicable in this situation,Footnote ⁵⁹ although it has been argued (partly by analogy with Köbler liability) that Article 13 ought to apply generally to acts or omissions by the judiciary which lead to violations of ECHR obligations.Footnote ⁶⁰ When such questions come before the ECtHR, it is surely foreseeable that states will raise res judicata based objections. That these objections could be dismissed does not matter. Rather, the point is that res judicata will very probably be raised and discussed if Article 13 is to operate to delay, or render unnecessary, recourse to the ECtHR. This discussion will occur by reason of the retention of the dispute within the same level of adjudication.

In sum, res judicata based concerns are always strongly implicated in Köbler liability cases since they involve a re-consideration, within the same judicial order, and at the request of the same complainant, of the EU law compatibility of a national rule. In contrast, res judicata concerns can be depicted as applying to varying degrees in different international law contexts. The greater the extent to which the international law context in question departs from the classical model of international law as being clearly separated from national law and as involving relations between states, the more pronounced res judicata concerns become. However, all international law contexts share the common feature of a transition between different levels of adjudication. It appears to be accepted that res judicata based concerns do not outweigh the power of the international tribunal to rule on the alleged wrong. The balance settles at a different point in Köbler liability actions. Here res judicata concerns have more weight because the dispute is retained within the national level of adjudication.

B. Köbler Liability as an Aspect of EU Integration

It is axiomatic that the EU has integration objectives which are not shared by any regime of international law. In the present context, this difference exerts two influences which pull in opposing directions. First, it would have been astonishing if Köbler liability had not been recognized bearing in mind that whole-state liability is an established international law feature. Secondly, however, it would also have been surprising if Köbler liability had been recognized without any tightening of liability conditions. This is because, in order for EU integration to be successful, it must occur with reference to the legal traditions of the Member States.Footnote ⁶¹ Neither the Court nor the Advocate General pointed towards a clear example of a jurisdiction which recognizes all the elements of Köbler liability—state liability for mistaken judgments of national courts of final appeal.Footnote ⁶² While Member States were told that all these elements have to be recognized in cases with an EU law dimension, there was a need for an accommodation. The tightened liability conditions could therefore be viewed as a concession to national legal orders, and as intended to enhance the prospects for embedding Köbler liability as an aspect of European integration.

In contrast, when international tribunals address state liability for judicial decisions, there is less need to think about any process of integration and prevailing national law traditions. To a much greater extent than the EU legal system, international law operates above and apart from municipal legal systems. The state unity theory is therefore permitted to result in undifferentiated liability conditions.

B. Judicial Cooperation in Community Law and International Law

More than the ECJ, Advocate General Léger devoted considerable attention to establishing that national supreme courts play a vital role in the implementation, enforcement and development of EU law.Footnote ⁶³ He referred to the ‘progressive development of a real Community judicial ethic’Footnote ⁶⁴ and identifies ‘the leading role played by supreme courts in the application of Community law’Footnote ⁶⁵ as evidenced by the obligation upon them to refer questions for preliminary rulings under Article 267.Footnote ⁶⁶ These considerations led the Advocate General to conclude that ‘[i]t is impossible to see how a Member State could prima facie escape all liability for the acts or omissions of its supreme courts when, specifically, those courts are responsible for applying and ensuring compliance with Community law. That would amount to an insuperable paradox.’Footnote ⁶⁷

There is also another paradox here. The very considerations which require the possibility of state liability for judicial conduct also suggest that the actual imposition of liability should be rare. Since, the ‘Community judicial ethic’ between the ECJ and national courts is the very foundation of the EU legal order,Footnote ⁶⁸ the possibility of consequences must attach to the breakdown of this ethic in individual cases. However, this ethic depends on a spirit of collegiality between Community and national judicial organs.Footnote ⁶⁹ The problem is that actually imposing state liability is more akin to a hierarchical structure, something which has been strongly resisted by several national supreme courts particularly the German Federal Constitutional Court.Footnote ⁷⁰ The paradox is therefore that state liability both underlines and undermines the ‘Community judicial ethic’. The riposte that the damages action is heard by a national court is not a complete answer if the lower court hearing the damages action seeks guidance from the ECJ. The way in which Köbler was decided may well have had more to do with this unarticulated consideration than the considerations discussed above.Footnote ⁷¹ Indeed, it is even arguable that the ECJ intended to send a signal to future litigants. If it is more difficult to establish state liability for judicial conduct, litigants are more likely to frame their damages action as a challenge against legislative and administrative shortcomings.Footnote ⁷² This reduces tension between the Court and national supreme courts.

Before turning to the international law context, a possible view that the tightening of the liability conditions has little to do with judicial cooperation can be addressed. This view could be based upon the ECJ's approach in Article 258 enforcement actions relating to judicial decisions. If cooperation is among the explanations for a tightening of the conditions of liability in Köbler actions, a comparable tightening should be observable in this analogous context. Looking at the leading case, it is indeed difficult to identify any tightening of the liability conditions. However, it is also clear from the ECJ's conclusion that the infringement was not ultimately based directly upon the supreme court decisions:

It is submitted that, in enforcement proceedings, it will usually be possible for the ECJ to base liability on such a failure to correct a judicial interpretation, rather than directly on the judicial decisions. This is because enforcement proceedings are only likely to be brought against established judicial interpretations rather than isolated judgments. As for why the ECJ chose to express its conclusion in this way, the need to preserve judicial cooperation is a possible explanation.

What can be said of the international context by way of comparison? Here, there is growing awareness of the benefits of various forms of interaction and cooperation among national judges and between national and international tribunals.Footnote ⁷⁴ A core aspect of the debate has been the role of national courts in enhancing the salience and impact of international law.Footnote ⁷⁵ Building on the work of Anne-Marie Slaughter, Benvenisti and Downs have recently posited collaboration between national and international tribunals as an essential means of enabling ‘global governance to flourish’, of ‘creating a more coherent international regulatory system’ and ‘modestly defragmenting the present system’.Footnote ⁷⁶ Yet it is probably not controversial to suggest that this is an area in which normative aspirations are running ahead of what can be observed. Thus, in response to Benvenisti and Downs, Lavranos adds a note of caution by referring to ‘a sliding scale of the direct impact of judgments of different international courts on national courts, the ECJ being at the top of this scale, followed by the ECtHR, and the ICJ at the bottom’.Footnote ⁷⁷ On the economic side, the decisions of WTO panels and the Appellate Body ought probably to be located closer to the bottom of this scale than the top. This is much as one would expect bearing in mind that implementing measures, at least in the US and the EU, expressly precludes private party reliance on WTO law.Footnote ⁷⁸ On the other hand, US courts have expressly recognized that panel and Appellate Body pronouncements are of persuasive value in the process of seeking to interpret ambiguous domestic legislation consistently with WTO obligations.Footnote ⁷⁹ In the EU context, Bronckers has referred to a number of cases in which a reasonable assumption could be made that the ECJ was partly motivated by an inclination to avoid conflict with Appellate Body rulings.Footnote ⁸⁰ He sees these cases as evidence of a ‘muted dialogue’ between the ECJ and the Appellate Body, contrasting this with a much more open dialogue between the ECJ and the ECtHR.

Judicial cooperation is clearly not something which is confined to the relationship between the ECJ and national courts. Yet, cooperation in the EU legal order is likely to retain a more developed and consistent quality than anything which can be observed in any international law setting by reason of the supremacy and direct effect of EU law coupled with the preliminary ruling procedure.Footnote ⁸¹ This has a bearing upon the conditions for state liability in respect of judicial conduct. It is potentially damaging to the interaction between the ECJ and national supreme courts for the ECJ to adjudicate on the substance of national court judgments. Limiting state liability (in effect) to cases where it can be reasonably inferred that the national court has been either incompetent in failing to understand the EU law dimension of a case, or has deliberately ignored this dimension, can be seen as a means of reducing this tension. For the most part, while state liability is present in the background, it is not imposed, thereby preserving the more subtle system of signalling cooperation or opposition which one would expect within a community of courts. Hence, in EU law, the tests for state liability in respect of judicial decisions can permissibly be applied in an especially strict manner. At least in relative terms, it is a less sensitive matter for an international court to adjudicate on whether national court judgments comply with international law. There is less of a community of courts whose ethos is capable of being damaged by the imposition of state liability.

C. Internal Tensions Caused by Köbler Liability Are Absent in the International Law Context

A number of Member States in Köbler objected to the possibility of state liability on the basis that it would cause internal tensions which have been well described by Anagnostaras. He sees state responsibility here as ‘entrusting the determination of the breach to a body belonging to the same system as the wrongdoer’. The lower court judge may ‘hesitate to reproach’ the activity of a superior court and, if the damages action is appealed to the supreme court, he questions ‘whether there is any point at all in accepting the availability of a damages action under circumstances permitting the alleged wrongdoer simply to confirm the legality of its contested action and to dismiss the relevant claim’.Footnote ⁸² Such concerns can be downplayed. As Advocate General Léger pointed out, the preliminary ruling makes it possible to ‘dispel any reasonable doubt as to the impartiality of the national court’.Footnote ⁸³ However, it may now seem as though Anagnostaras' perspective was remarkably prescient in light of the litigation in Cooper.Footnote ⁸⁴ In this case, Köbler liability was considered by the High Court in respect of a Court of Appeal decision. The High Court did not make a reference and neither did the Court of Appeal before confirming the legality of its own previous judgments.Footnote ⁸⁵ Concerns about internal tensions and lack of impartiality may therefore emerge to be well founded as the national reception of Köbler liability is tested in future cases.

In this eventuality, the burden on the applicant of satisfying stringent tests which can be strictly applied can be seen as a means of defusing this tension. Some internal tension may be caused by the national court merely hearing the action. However, the occurrence which causes the most tension—confirmation of state liability—will be highly exceptional by reason of the permission to apply the key test in a strict manner. In the international law context, the obvious difference is that state responsibility is evaluated and imposed by judicial bodies and tribunals which are external to the national court system so that the need to minimize internal tensions clearly does not apply. The externality of the international judicial body means that it can evaluate and impose state responsibility in a relatively uninhibited manner compared with a national court.