Peremptory norms of international law (jus cogens)

Doctrinally, the notion of a hierarchy existing within international law finds support in the concept of peremptory norms or jus cogens.^{Footnote 23} Indeed, Article 53 of the Vienna Convention on the Law of Treaties (VCLT) defines jus cogens as a norm of ‘general international law [which is] accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character’.^{Footnote 24} This definition reflects the idea that the peremptory norm is no ordinary norm which states are allowed to derogate from or contract out of. The hierarchy implied would be of a substantive nature, in the sense that it would be based on the nature or character of a particular norm, rather than the formal source from which the norms originate.^{Footnote 25}

An analysis of judicial practice confirms that various judicial bodies have formally recognized the special nature of jus cogens norms and that these bodies are not particularly concerned with the fact that the operation of this concept was initially confined to treaty law.^{Footnote 26} In addition, most of the norms on the (still very short) list of peremptory norms are of a human rights nature.^{Footnote 27} Judicial bodies have frequently acknowledged the peremptory status of, in particular, the prohibition of genocide and the prohibition of torture.^{Footnote 28}

However, in practice the relevance of the hierarchically superior nature of jus cogens norms for the purpose of norm conflict resolution remains limited. While judicial bodies are on one hand willing to recognize formally the peremptory character of the prohibitions of genocide and torture, they have yet to attach consequences to such peremptory status in the context of norm conflict resolution. For example, an analysis of judgments and arbitral awards in international investment law does not show a single rule of hierarchy which would be applied consistently on a widespread basis. In particular, no rule has emerged in accordance with which an investment that violated a jus cogens norm was not entitled to protection of the rules governing investment law – at least not in the context of investor-state cases.^{Footnote 29}

The only area of international law in which jus cogens may increasingly be playing an important role in the resolution of norm conflicts seems to be that of state immunity. However, even in this instance the relevant case law is coming from one particular jurisdiction. The Italian courts have attached significant weight to the values underpinning jus cogens norms and the need for enforcing these obligations (as well as the values that they represent) effectively. In Ferrini the Court of Cassation waived the state immunity of Germany in relation to compensation claims for international crimes committed during World War II.^{Footnote 30} In Lozano the Court of Cassation did not waive the immunity ratione materiae of a United States military official from prosecution in Italy, as the act of killing an Italian intelligence officer in Iraq under the circumstances did not amount to an international crime. However, the Court nonetheless confirmed in an obiter dictum that immunity against prosecution would not apply where an international crime was at stake.^{Footnote 31} According to Philippa Webb, these are rare instances where the courts openly confirmed the (potential) trumping effect of a peremptory norm. However, this practice of domestic courts is very limited and cannot yet be generalized as being applicable across jurisdictions.^{Footnote 32} Moreover, the Ferrini case has resulted in litigation between Germany and Italy before the ICJ. In this case, the ICJ rather categorically and unambiguously rejected the automatic trumping effect of peremptory norms.^{Footnote 33} From now on this line of argument will be even more difficult to follow in domestic and international litigation.

Moreover, for the purpose of resolving norm conflicts in practice, other formal qualities such as non-derogability can be as or even more relevant than jus cogens. This is particularly true in the context of extradition, where the obligation not to extradite persons to countries where they will be exposed to torture (non-refoulement) is an important consideration before extradition may take place.^{Footnote 34} When refusing to give effect to the obligations under an extradition treaty due to a fear that this may result in torture of the extraditee, courts usually do not explicitly refer to the peremptory nature of the prohibition of torture. Instead, the fact that the prohibition of torture is regarded as absolute, allowing no derogation, seems to be the decisive factor.^{Footnote 35}

One may therefore conclude that from a conceptual point of view, the notion of jus cogens cannot exist without some sort of norm hierarchy within international law.^{Footnote 36} Judicial practice, however, demonstrates that this hierarchy may be no more than rhetorical or formal, as in practice hardly any use is made of the notion of jus cogens as a tool of norm conflict resolution. With the exception of developments pertaining to immunities in recent Italian decisions, judicial bodies have persistently refrained from attaching any significance to the special nature of jus cogens obligations (or the values underpinning these obligations), for the purpose of overriding conflicting international obligations binding on the state in question.

Article 103 of the United Nations Charter

Outside the area of jus cogens the main contender for claiming a hierarchically superior status in the international legal order would be Article 103 of the United Nations Charter (the Charter). It is arguable that Article 103 would present a source-based hierarchy rather than a value (substance) based one. It attributes precedence to obligations arising under the Charter on the basis of their origin, namely that they stem from the United Nations Security Council (itself a treaty creation).^{Footnote 37} A plausible argument can also be made that Article 103 does represent a value based hierarchy, as it is directed at giving effect to the enforcement of the purposes of the United Nations, notably the maintenance of international peace and security.^{Footnote 38} In another view, Article 103 does not establish any hierarchy, but was included in the treaty framework of the Charter as a conflict rule. It does not intend to elevate all obligations under the Charter to a hierarchically superior position. Instead, it merely attaches a trumping effect to those obligations arising within the treaty framework of the Charter and which conflict with specific obligations arising from treaties or customary international law.^{Footnote 39}

Hence, Article 103 is not necessarily a rule of hierarchy. According to Antonios Tzanakopoulos, Article 103 does not establish that obligations under the Charter are non-derogable except by a norm of the same or higher rank. Instead, it merely establishes that on occasion the obligations under the Charter may lead to the non-application of other obligations under international law.^{Footnote 40}

The opposite interpretation is also possible. In Al-Jedda, as decided by the (then still) House of Lords, Lord Bingham of Cornhill stated that in the context of Chapter VII of the Charter, ‘article 103 should not . . . be given a narrow, contract-based, meaning. The importance of maintaining peace and security in the world can scarcely be exaggerated’.^{Footnote 41} It could be argued that Lord Bingham thus suggested that Article 103, in combination with Article 25⁴² and Chapter VII of the Charter, also has an important substantive value. Hence, the hierarchy stemming from Article 103 might not only be source related but also substantive – originating in the concern for international peace and security.^{Footnote 43}

In Nada the Swiss Federal Supreme Court had to decide whether binding United Nations Security Council resolutions that obliged member states to freeze the assets of individuals blacklisted by the Security Council’s Sanction Committee, due to their suspected involvement with international terrorism, took precedence over, inter alia, the right to a fair hearing under Article 6(1) of the European Convention of Human Rights (ECHR). The court, relying on Article 103 of the Charter, answered this question in the affirmative, regarding the operation of Article 103 as an ‘effect of normative hierarchy in international law’.^{Footnote 44} This explicit acknowledgement of Article 103 as a manifestation of normative hierarchy remains an isolated example in judicial practice. However, when the case subsequently proceeded to the ECtHR, the latter concluded that the Swiss court did not sufficiently use the room at its disposal for interpreting the Security Council resolution in a human-rights-friendly manner. According to the ECtHR, the choice between giving effect to the Security Council resolution and human rights obligations did not constitute a narrow normative conflict, i.e., it did not imply that compliance with one obligation resulted in the breach of another.^{Footnote 45} Nevertheless, the ECtHR in this case very cautiously resorted to the unusual factual circumstances of the case and did not make a straightforward argument that the Security Council cannot demand a violation of human rights.^{Footnote 46}

In Kadi, the European Court of Justice (ECJ) did not address the issue of the hierarchical standing of Article 103 within international law, a point to which will be returned below.^{Footnote 47} As a result, it seems that the jury is still out on the nature of the special standing of Article 103 of the Charter within international law.

All in all, judicial practice demonstrates that norm hierarchy may be no more than a theoretical (formal) concept in international law. While the impact of jus cogens in judicial practice has thus far been limited to the formal acknowledgement of its existence, it remains uncertain whether Article 103 of the Charter represents a norm hierarchy at all.

The irrelevance of traditional conflict rules

The traditional conflict rules, originating in the general principles of law as well as in the VCLT, are lex specialis derogat legi generali and lex posterior derogat legi priori.^{Footnote 49} When it comes to the resolution of norm conflicts (whether narrow or broad) discussed in this contribution, judicial practice reveals these traditional conflict rules are unlikely to be of relevance. This can be explained by the fact that neither of these principles is well suited to resolve the type of norm conflicts in question. Indeed, if a new treaty regulates the same subject matter as a previous treaty, this cannot be described as a norm conflict but rather means that the old legal regulation has been replaced by the new one.^{Footnote 50}

The principle of lex specialis, a general principle of international law,^{Footnote 51} implies that whenever two or more norms deal with the same subject matter, priority should be given to the norm that is more specific. However, this principle would only become relevant where the conflicting norm indeed represented a lex generalis. Since the conflicts that form the object of the analysis all stem from different specialized regimes, one was in fact confronted with one lex specialis versus another.^{Footnote 52} This point is aptly articulated by Andreas Ziegler and Bertram Boie in relation to disputes between international trade rules and human rights obligations, which can described as an inter-regime conflict that could not be resolved by principles (such as lex specialis) designed for resolving intra-regime conflicts.^{Footnote 53}

The lex posterior principle, as articulated in Article 30 of the VCLT, implies that when all the parties to a treaty are also parties to an earlier treaty on the same subject, the earlier one would only apply to the extent that its provisions are compatible with those of the later treaty.^{Footnote 54} The applicability of this principle is, however, complicated by the fact that it remains unclear how it should apply to subsequent treaties that do not have identical parties.^{Footnote 55}

In addition, there remains disagreement as to what would constitute treaties ‘relating to the same subject-matter’. If the principle is applied strictly, inter-regime conflicts would fall outside the scope of the lex posterior principle.^{Footnote 56} However, if the principle implied that treaties deal with the same subject matter when the fulfilment of the obligation under one treaty affected the fulfilment of the obligation under another, the lex posterior principle would be applicable.^{Footnote 57} But even then a straightforward prioritization on the basis of the chronological order of the obligations is unlikely and most likely not satisfactory.^{Footnote 58}

The only principle of the VCLT significant for the resolution of the norm conflicts at stake is the principle of systemic integration contained in Article 31(1)(c), which is also accepted as forming a part of customary international law.^{Footnote 59} This principle determines that when interpreting a treaty, any relevant rules of international law applicable in the relations between the parties will be taken into account, such as other treaties, customary international law and general principles of law.^{Footnote 60} Although judicial bodies do not necessarily refer to this principle explicitly, they frequently apply it in practice.^{Footnote 61}

Reconciliation through restrictive interpretation

Rather than resolving norm conflicts through the trumping of one right or obligation by another, judicial bodies engage in the reconciliation of the competing rights and/or obligations. This attempt at norm conflict resolution through harmonious interpretation can have a significant impact on the scope of the norms in question.

The second section above suggested that the balancing of competing rights and obligations by judicial bodies may result in the implicit recognition of a human rights based hierarchy in international law. This would be the case where courts tended to interpret the scope of the human rights obligation broadly, at the expense of the scope of the conflicting right or obligation.^{Footnote 62} However, the case law analysis reveals that the only judicial bodies likely to give implicit recognition to the supremacy of international human rights obligations are those with a functional bias in the sense that they were created for the very purpose of protecting human rights. Other courts are more inclined to avoid a conflict through interpretation and in the process also eliminate any hierarchy.^{Footnote 63}

The absence of a human rights based hierarchy would not necessarily mean that human rights norms have no role to play as a connecting factor between functionally fragmented legal regimes. There is room for human rights considerations in the interpretative process in which judicial bodies engage and it is possible that the impact of human rights in these processes may grow over time. It would, however, be premature to regard human rights as already constituting a strong and well-developed common thread amongst the various legal regimes within the international legal order.

To illustrate the functional bias referred to above, it is illuminating to compare the treatment of the right to property by human rights bodies and arbitral tribunals respectively. The Inter-American Court of Human Rights has shown a tendency to favour the human right to property as guaranteed in Article 21 of the Inter-American Convention on Human Rights over competing investment claims, in particular in relation to the property rights of indigenous communities.^{Footnote 64} A similar position has since also been adopted by the African Commission on Human and Peoples’ Rights.^{Footnote 65} However, arbitral tribunals are less inclined to follow a similar reasoning and even if a particular decision effectively results in the protection of the human rights of an indigenous community, the rationale of the decision is likely to be based on other (e.g. investment) principles.^{Footnote 66}

Moreover, it cannot be assumed that specialized human rights courts will necessarily attach a broad scope to human rights obligations whenever presented with a norm conflict. In fact, one reason for the limited practical relevance of jus cogens obligations is the very narrow normative scope that all judicial bodies tend to attribute to the peremptory norms of international law. As a result they succeed in avoiding a norm conflict altogether, as it is unlikely that a conflict between the jus cogens norm and other norms would arise under such circumstances.

A very illustrative example concerns the prohibition of torture, where the scope of the jus cogens obligation seems to encompass only the prohibition of torture as such (i.e., the negative obligation not to engage in torture).^{Footnote 67} The norm conflict which often arises in the torture context with customary obligations pertaining to immunity does not, however, relate to this particular negative obligation. Instead, the conflict exists between customary obligations pertaining to immunity and treaty obligations guaranteeing the right of torture victims to access to a court of law. The right (and corresponding obligations to provide) access to a court under these circumstances does not constitute a matter of jus cogens, as the normative scope of the peremptory prohibition to engage in torture does not (yet) encompass an ancillary obligation to waive immunity.^{Footnote 68} Such a wider interpretation of the normative scope of jus cogens has been suggested by the dissenting judges in Al-Adsani ^{Footnote 69} and followed in recent Italian decisions. However, it has not yet received wide recognition in judicial practice and in light of the ICJ’s decision in Germany v Italy,^{Footnote 70} it is unlikely that the Al-Adsani dissent will gain the upper hand in judicial decisions.

Another illuminating example of conflict avoidance through a narrow interpretation of the human rights obligation at stake concerns the issue of diplomatic assurances in extradition law.^{Footnote 71} Courts have allowed extradition to states known for engaging in torture practices in instances where the latter have given assurance that this would not occur in relation to the extraditee in question.^{Footnote 72} The conflict between the obligation to extradite in accordance with an extradition treaty and the human rights obligation to refrain from extradition where this may result in torture is thereby prevented by narrowing down the scope (including the absolute character) of the latter obligation. It is only violated if the extraditing state agrees to extradition without having received assurances from the requesting state that the extraditee will not be subjected to torture. The prohibition, therefore, does not apply broadly in the sense that extradition to a state with a notorious torture record is always prohibited. In the process, the absolute character of the prohibition of torture itself may also be undermined, as the extraditee might still be tortured if the diplomatic assurances were not honoured subsequent to the extradition.^{Footnote 73}

Similarly, when faced with extradition or deportation requests courts tend to apply a high threshold when determining what constitutes torture, inhuman or degrading treatment^{Footnote 74}, as well as evidentiary proof that the risk to the individual is specific and personal.^{Footnote 75} These requirements can also result in narrowing down the scope of the prohibition.

Another example of conflict avoidance through interpretation that affects the nature or scope of the conflicting norms concerns conflicts between human rights obligations and environmental obligations. When dealing with competing human rights and environmental obligations, judicial bodies resolve the conflict by interpreting environmental interests into, for example, the principle of human dignity or the right to life. This is done by relying on a mixture of international and domestic human rights instruments, on the assumption that the goals of environmental protection and human rights are both aimed at ensuring human well-being.^{Footnote 76} This technique does not remove the norm conflict but shifts it to the level of an intra-regime conflict (within the human rights regime itself). It is usually resolved through a balancing act that narrows down the scope of all the rights and obligations at stake.^{Footnote 77}

Conflict avoidance through formalistic interpretation

In addition to techniques of interpretation that affect the substance (scope) of conflicting rights and obligations, courts also engage in formalistic techniques of conflict avoidance. One such technique is the distinction between substantive and procedural law, as applied in relation to the law of immunities.^{Footnote 78} In line with this view, obligations pertaining to immunities cannot conflict with the jus cogens norm encompassed in the prohibition of torture, as the former is a matter of procedural law while the latter constitutes substantive law.^{Footnote 79}

Closer scrutiny reveals that this argument is only accurate in as far as it concedes that there is no conflict between the peremptory prohibition against torture and a lower-ranking norm in international law. However, the argument is not accurate in as far as it suggests that the conflict is between a substantive and procedural norm, respectively. As has already been illustrated above, the actual conflict in this instance exists between customary obligations pertaining to immunity and treaty obligations pertaining to the right to access to court. Both categories of obligations are arguably procedural in nature.^{Footnote 80}

Another formalistic conflict avoidance mechanism applied in relation to the law of immunities concerns the distinction between private and official acts, when the immunity ratione materiae of a state official is concerned. By arguing that crimes under international law (such as the prohibition of torture) cannot constitute ‘official’ acts, but must be qualified as ‘private acts’ of the individual the act in question is excluded from the scope of the immunity ratione materiae. As a result, a norm conflict with the right to access to court or the right to a remedy will not arise.^{Footnote 81} However, it is doubtful whether the labelling of torture as a private act is convincing, since torture by state officials almost by definition involves the support of the state apparatus which should also incur state responsibility.^{Footnote 82}

Furthermore, domestic and supranational courts occasionally retreat behind the formal argument of dualism as a method of conflict avoidance. The Kadi case before the ECJ was a prime example of withdrawal behind the dualist veil for the purpose of conflict avoidance.^{Footnote 83} The ECJ reshaped the norm conflict as a ‘domestic’ one that had to be resolved on the basis of European Union law. Although effectively giving precedence to human rights protection over security concerns, this decision was based on the value system of the European Union itself. The ECJ did not address the conflict between the international human rights obligations of its member states and their obligations pertaining to international peace and security under the Charter.^{Footnote 84} This decision forms a stark contrast with the Nada case of the Swiss Federal Tribunal, which remains a rare and controversial example of open support for the hierarchical superiority of Security Council decisions vis-à-vis international human rights obligations.^{Footnote 85}

A further illustration of conflict avoidance through the ‘dropping of the dualist veil’ was the Samantar case in which the United States Supreme Court held that the Foreign Sovereign and Immunities Act (FSIA) did not grant a former Prime Minister and Defence Minister of Somalia immunity against a civil claim for acts of torture performed in his official capacity.^{Footnote 86} The court concluded that nothing in the text of the FSIA suggested that the term ‘foreign state’ should be read to include individual officials acting on the state’s behalf. The court thus focussed exclusively on the interpretation of a domestic law and did not address the possibility of Samantar enjoying immunity under international law, nor whether that would result in a conflict with human rights obligations.^{Footnote 87}

In sum, whether confronted with broad or narrow norm conflicts, judicial bodies rarely resolve them by means of trumping through hierarchically superior norms or any other rules of automatic precedence. Rather, judicial bodies resort to systemic integration through reconciliation and sometimes formalistic approaches of conflict avoidance. A human rights bias in this exercise can be (partly) found in the work of specialized human rights bodies but is not a general pattern. Like other judicial bodies, human rights courts are prone to achieve a balance between the different applicable international obligations in the case at hand.