In Section 3.B. of the judgment (paragraphs 92 – 97) the Court responded to, and engaged with, the second strand of Italy’s second argument, which suggested an exception to state immunity where a conflict existed between state immunity rules and the enforcement of a rule with peremptory character. Italy had advanced the claim that such a conflict existed in this case, because rules on state immunity required the forum state to offer immunity to a state whose armed forces had committed grave breaches of the law of armed conflict—that is, breaches of obligations arising under peremptory norms of general international law.
Italy sought to invoke this putative substantive conflict between the peremptory character of the norms under which Germany’s obligations arose, and the rules on state immunity, as a justification for the Italian courts’ denial of immunity to Germany. In Ferrini v. Federal Republic of Germany, Italy’s Corte di Cassazione had relied on this “normative hierarchy argument”. The decision did not use the term jus cogens, but it is clear from the Corte di Cassazione’s use of the term “non-derogable” that it was referring to peremptory norms.
Italy argued that in the case of a substantive conflict between the application of the peremptory rule and the rules on state immunity, the latter must yield to the former, because it is a feature of a peremptory rule that it prevails over non-peremptory rules. Germany had denied this argument vigorously throughout its written and oral submissions, and had drawn attention to the distinct areas to which immunity rules and peremptory rules pertain.
The Court accepted as a definition of a peremptory rule “one from which no derogation is permitted” (para. 95), incidentally only the first limb of the two-pronged 1969 and 1986 Vienna Convention definition. The Court rejected Italy’s argument, because it found that no conflict existed between rules on the jurisdictional immunity of states and the enforcement of obligations arising under the law of armed conflict. The two sets of rules, the Court found, governed different matters. Immunity rules are procedural. A rule’s peremptory character, on the other hand, pertains to matters of legality and responsibility. (This reason also underlies the Court’s finding that there was no temporal conflict in applying present-day rules on jurisdictional immunity—rather than those contemporaneous with the breaches occurring in 1943-45, whose legality remained governed by the substantive law contemporaneous with those events.) Consequently, extending jurisdictional immunity to a state in breach of grave violations of the law of armed conflict does not amount to recognizing as lawful a situation brought about by the serious breach of an obligation arising under a peremptory norm of general international law. Nor does it constitute rendering aid or assistance in maintaining such a situation. The Court seemed to accept this dual negative obligation, reflected in Article 41(2) of the International Law Commission’s Articles on the Responsibility of States for Internationally Wrongful Acts, as the correct reflection of the law (para. 93).
The Court observed that Italy’s argument was not strengthened by an alternative focus on the duty to make reparations, rather than on the grave violations of the law of armed conflict. In any event, the Court noted, it was difficult to accept that there existed under general international law a non-derogable duty to pay reparation to each victim (para. 94).
The Court proceeded to reject the argument that a non-peremptory rule—here the rules on the jurisdictional immunity of a state—may not be applied if doing so would hinder the enforcement of a peremptory rule, even in the absence of a direct conflict between the two sets of rules (para. 95). This is an important theoretical contribution to the understanding of the enduringly difficult notion of peremptory norms in international law: a statement on the limited legal effects of peremptory rules. The legal consequences that a breach of such an obligation entails do not extend to displacing rules that may merely render the effective enforcement of a peremptory rule more difficult to achieve. Notice that Italy’s argument would entail not a permission to deny immunity in these circumstances, but an obligation not to offer immunity.
The Court’s treatment of the procedure/substance divide in the section on peremptory norms is short. But it is a distinction, indeed a fundamental one, that runs throughout much of the judgment and which ultimately proved fatal to many aspects of Italy’s arguments. Rules on state immunity, which are procedural, do not derogate from peremptory rules, which are substantive, the Court noted. The Court’s position is consistent with its posture on the closely related question on personal immunity in Arrest Warrant (Democratic Republic of the Congo v. Belgium). Moreover, the Court’s decision not to attach jurisdictional consequences to the breach of an obligation arising under a peremptory norm of general international law is consistent with its decision in Armed Activities (Democratic Republic of the Congo v. Rwanda) not to attach any legal consequences in those circumstances to its own jurisdiction.
Finally, the ICJ noted that it found no state practice in national court decisions or national legislation to support Italy’s position. Apart from Italy’s own courts, no other national courts have found an exception to state immunity to exist where the obligation breached arose under a peremptory norm of general international law. The Court cited such decisions as Bouzari v. Islamic Republic of Iran (Ontario Court of Appeals) and Jones v. Saudi Arabia (House of Lords). The Court also cited various national court decisions in which Germany’s immunity for alleged violations arising out of the events of the Second World War had been upheld. Moreover, the Court noted, since the Greek Special Supreme Court in Margellos v. Federal Republic of Germany had rejected the reasoning of the Greek Supreme Court in Prefecture of Voiotia v. Federal Republic of Germany, and Greek courts were under instructions to follow the reasoning in Margellos, Greek practice undermined rather than supported Italy’s argument.
The six paragraphs of the judgment are the longest discussion of peremptory norms of international law in any ICJ judgment to date. The Court’s earlier references to the jus cogens or to peremptory norms had remained short and tentative, and it only accepted the concept in its 2006 judgment in Armed Activities (Democratic Republic of the Congo v. Rwanda).
In Jurisdictional Immunities, the Court did not unequivocally accept that the rules in question possess a peremptory character. It proceeded with its reasoning “[a]ssuming for this purpose that the rules on the law of armed conflict … are rules of jus cogens” (para. 93). We may contrast this with the Court’s position in Armed Activities, where it said in paragraph 64 that the prohibition of genocide “assuredly” had peremptory character. The Court later referred to this statement in paragraph 161 of its 2007 judgment in Application of the Genocide Convention (Bosnia and Herzegovina v. Serbia and Montenegro). Curiously, however, when referring to its judgment in Arrest Warrant, the Court notes the “criminal violations of rules which undoubtedly possess the character of jus cogens” involved in that case. The judgment in Arrest Warrant had used neither the term peremptory norm(s), nor jus cogens.
However, the characterization of specific substantive rules as peremptory is only of secondary interest. The relevant legal issue concerns the effects, if any, that this peremptory character gives rise to with respect to rules on state immunity. In both Jurisdictional Immunities and in Armed Activities the Court tells us what legal consequences peremptory norms do not have for state immunity and jurisdiction, respectively. We learn from Jurisdictional Immunities that the legal consequences of peremptory norms must be independently grounded and cannot be inferred freely. Specifically, this means that they do not require the setting aside of rules whose application may merely hinder the enforcement of a peremptory rule. The judgment introduces the idea that the various legal consequences associated with a rule’s peremptory character require independent identification and grounding. Legal consequences do not follow from the mere fact that a legal rule putatively has a peremptory character.
The Court unfortunately does not engage explicitly with the distinction, repeatedly raised by Germany in its written and oral submissions, between primary and secondary rules. Germany uses this distinction to underline how peremptory legal consequences must have an independent basis and cannot merely be inferred theoretically. Had the Court addressed this distinction it may have contributed in a clearer fashion to the understanding of these peremptory legal consequences.