4 Interpretation and modi fi cation
5.5.1 International law’s sui generis hierarchies
Large parts of traditional international legal scholarship161 do not believe that the sources of international law are ordered so that one source is dependent for its validity upon another source (one possible exception being acts of international organs). Yet this form of validity-dependence is the core of the Pure Theory of Law’s conception of superiority of norms. Without a co-ordinating super- structure of norms from which the sources derive, the consequence is unavoidable that customary international law and international treaty law are separate norma- tive orders (Section 6.3.2). As noted above, such a claim must overcome the hurdle of separation of normative orders. ‘Derogation can only occur within one and the same normative order.’162
Yet in international legal doctrine hierarchy has been utilised in a different manner163 akin to Merkl’s hierarchy of derogation (Sections 5.3.2 and 5.5.2).
Scholars have ascribed a hierarchically higher position to certain phenomena of international law, with powers to derogate from or not to allow the creation of conflicting international law norms. We will look at ius cogens and Article 103 UN Charter as the two least controversial claims to superiority in international law in turn to find out whether they are stong enough to found such a hierarchy on their own merits and whether their claim to be a lex superior can resolve conflicts between norms of international law independently of the validity-dependence relationship discussed in the other sections of this chapter.164
(1) Ius cogens, as envisaged by international legal doctrine165 and as partially expressed in the Vienna Convention, has multiple features. (a) A ius cogens norm is
160 ‘Die lex posterior und lex specialis gehen . . . ja nicht deshalb vor, weil sie jünger bzw. spezieller sind . . ., sondern deshalb, weil ihr Vorrang . . . angeordnet ist und diese Anordnung ihrerseits Vorrang genieòt.’ Schilling (1994) supra note 40 at 400–401.
161 Pace Kelsen: Kelsen (1952) supra note 64 at 314.
162 ‘Derogation kann nur innerhalb ein und derselben normativen Ordnung erfolgen.’ Kelsen (1979) supra note 8 at 102 (Ch 29 III).
163 The ILC cautions against using domestic analogies, for it sees ‘hierarchy’ in a specific inter- national law sense as well: International Law Commission, Report on the work of its fifty-fourth session (29 April–7 June and 22 July–16 August 2002), A/57/10 (2002) 240.
164 Robert Kolb, for example, argues that ‘[h]ierarchical value is . . . often to be found in the norm itself, rather than in the source of the norm’. (Kolb (1998) supra note 68 at 77).
165 The idea of ius cogens is supported by positivists (Kelsen (1952) supra note 64 at 323, 344) and natural lawyers alike (Verdross and Simma (1984) supra note 3 at 328–334).
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created in a qualified procedure as against other international law. Article 53 VCLT requires that it be ‘accepted and recognised by the international com- munity of States as a whole’, whereas customary international law-creation does not require that the states ‘as a whole’ support practice by their opinio iuris. This difference is reminiscent of a higher quorum for the creation of constitutional norms as against other statutes. Like many other constitutional documents, the Austrian Federal Constitution requires a consensus-quorum of two-thirds of votes cast in the first chamber of Parliament for the creation of constitutional laws.166 (b) Scholarship often describes ius cogens norms as so qualified by virtue of the substance of their content. ‘The content of a jus cogens rule . . . has to be of great or even fundamental importance to the international community.’167 The concept of peremptory norms is argued to introduce an element of ‘international public order’168 into what seems to be regarded as a voluntaristic and private law- oriented legal system. The notion of ‘public order’ is invariably influenced by natural law thinking, e.g. treaties contra bonos mores.169
(c) Another element of ius cogens as conceived in international legal scholarship is that it constitutes ius non dispositivum, i.e. ius cogens in the original Roman law sense (cf. Section 5.2.3). Civil Codes allow private individuals to ‘contract out’ of certain of its provisions. Article 3 of the Rome Convention on the Law Applicable to Contractual Obligations 1980170 gives priority to the contractual regulation of the applicable law for a private contract. In certain cases, however, a statute may reserve the ‘right’ to exclusively regulate a matter – thus curtailing the private freedom of contract. (d) Closely connected hereto is the other original Roman law feature. Because ius cogens is ius non dispositivum, any contrary regulation would be derogated from or would be void ab initio (not become a valid norm). Thus, Articles 53 and 64 VCLT purport to void treaties in conflict with ius cogens and claim to establish a hierarchy of derogation171 independent of the hierarchy of validity-dependence.
However, the concept of ius cogens as envisaged in doctrine – at least outside the Vienna Convention’s scope of application – is problematic, especially as concerns its justification and its effects in a norm-conflict. First, it is unlikely that customary international law is ius dispositivum by default. As mentioned above (Section 5.2.3), norms claim to be observed. Prohibitions or obligations posit how their subjects
166 Art 44 Abs 1 Bundes-Verfassungsgesetz, BGBl 1930/1 idF BGBl I 2003/100.
167 G.J.H. van Hoof, Rethinking the sources of international law (1983) 153; Alfred Verdross, Jus dispositivum and jus cogens in international law, 60 American Journal of International Law (1966) 55–63 at 58.
168 Czaplin´ski and Danilenkow (1990) supra note 10 at 10; Georg Schwarzenberger, The problem of international constitutional law in international judicial perspective, in: Jost Delbrück, Knut Ipsen, Dietrich Rauschnig (eds), Recht im Dienst des Friedens. Festschrift für Eberhard Menzel zum 65. Geburtstag am 21. Januar 1976 (1975), 241–148 at 243.
169 Verdross (1966) supra note 167 at 61; Verdross and Simma (1984) supra note 3 at 328.
170 European Communities, Official Journal L 266, 9 October 1980 at 1–19.
171 Pauwelyn (2003) supra note 4 at 98.
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ought to behave. No norm of international law, whether customary or con- ventional, by default requires observance only in the case that no opting-out has taken place. The assumption of the ius dispositivum character by scholars does not make it true. If a norm does not actually require observance unless there is inter se regulation, it simply does not contain such an exception. The presumption is actually the reverse of the orthodox position: all law is ius cogens (ius non dispositivum) unless it says it is ius dispositivum. The question is not ‘whether all norms of inter- national law have the character of jus dispositivum’,172 but whether any do. Indi- vidual customary norms (or the law on customary law-creation) would have to specify this – and that is not likely. On the other hand, as a non-dispositive quality is the default for norms, there is no a priori necessity for an increased quorum for their creation.
Second, there are few arguments on the normative foundation or basis of the concept of ius cogens in international law. The concept would have to have a founda- tion in positive law. Proponents have to show that ius cogens fulfils the criteria of law- making of one of the sources of international law. Plainly, ius cogens is part of the VCLT. There is no problem with this, only with the absolutisation that occurs when its scope is extended outside the limit of what the VCLT can achieve (Section 5.3.2). If ius cogens itself is a customary international law norm, the problems would start mounting up. As a norm of customary international law, would the concept of ius cogens itself be a ius cogens norm? How can it justify itself ? If it is a simple norm of customary law, can the very notion be changed by a later customary norm or ‘opted out’ in treaties? The argument here is not that there is absolutely no such thing as ius cogens, but that outside the Vienna Convention’s scope it does not exist as conceived by the Vienna Convention and traditional legal scholarship.
Third, throughout this chapter the claimed power to derogate of certain
‘logical rules’, effectivités or norms has been questioned. If one applies this to ius cogens, one may find that there is little reason to allow for derogating force there either. Why should one norm – even if ‘accepted and recognised by the inter- national community of States as a whole’ – destroy another norm simply because it says so? The sui generis hierarchy created by international legal scholarship does not accord with the hierarchy of validity, so why should ius cogens’ claim be privileged?173 Verdross argues that natural lawyers have fewer problems with this notion than positivists do. After all, the ‘idea of a necessary law which all states are obliged to observe’174 is the claim of a fictional norm of a normative order beyond positive international law. What distinguishes that claim from a person’s personal claim to void any judgments directed against that person by a municipal criminal court?
172 Verdross (1966) supra note 167 at 55 (emphasis added).
173 Ius cogens is not lex superior through its form, but its content, argue: Kolb (1998) supra note 68 at 76, 80; Vranes (2005) supra note 116 at 400.
174 Verdross (1966) supra note 167 at 56.
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(2) The case for a sui generis hierarchy can be countered with respect to Article 103 UN Charter as well. Article 103 is an obligation binding upon the member states of the United Nations,175 but what makes the Charter different from other treaties? Article 103 does not specify exactly what happens to the obligations under other treaties176 – it does not say whether the validity of the other norm is ended – except that the Charter shall ‘prevail’.177 This could mean that international lawyers ought to pragmatically ignore the non-Charter norm (Section 5.4). Rudolf Bernhardt argues that at least in some cases the other treaty is either void ab initio or voided.178 Yet even if ‘[w]orld peace itself may depend on respect for the higher rank and binding force of the Charter as emphasised by Art. 103’,179 the maintenance of world peace is not a sufficient justification for derogatory powers. Also, because in norms bindingness equals existence and because existence is not gradual, there can be no higher binding force. All norms a priori have binding force and equal force at that. Politically, the Charter is the most important treaty valid today; it has a fundamental position in international relations. This politico-moral importance itself does not translate to a status as superior norm. It does not translate into derogatory power vis-à-vis other treaties. There still is a conflict between two treaties. Even if one of them claims to ‘prevail’ over the other, that does not mean that it actually does.
The traditional international law hierarchies, as they are not based upon validity-dependence by law-creation, are claims. They face the same problems as all other such claims discussed above. Perhaps Kelsen wanted to avoid the difficult and seemingly unsolvable questions of norm-conflicts in international law through the establishment of a clear hierarchy between the sources of inter- national law. We will next turn to the question whether Merkl’s and Kelsen’s concept of the Stufenbau, i.e. a hierarchy based upon a norm’s source of validity, fares better at ‘privileging’ one norm over another. Does norm-conflict vanish before a ‘truly’ superior norm?180
175 Zdizislav Galicki, Hierarchy in international law: jus cogens, obligations erga omnes, Article 103 of the Charter of the United Nations, as conflict rules, in: International Law Commission, Documents of its fifty-sixth session, Geneva 3 May-4 June and 5 July-6 August 2004, ILC(LVI)/
SG/FIL/CRD.5 (2004) 4 (para 7).
176 Rudolf Bernhardt, Article 103, in: Bruno Simma (ed.), The Charter of the United Nations. A commentary (2nd ed. 2002) 1292–1302 at 1295 (RN 6).
177 Re-emphasised by the Court: Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v.
United States of America), Jurisdiction and Admissibility, Judgment of 26 November 1984, ICJ Reports (1984) 392 at 440; Questions of Interpretation and Application of the 1971 Montreal Convention arising from the Aerial Incident at Lockerbie (Libyan Arab Jamahiriya v. United Kingdom), Preliminary Objections, Judgment of 27 February 1998, ICJ Reports (1998) 9 at 31 (para 39).
178 Bernhardt (2002) supra note 176 at 1297 (RN 15).
179 Bernhardt (2002) supra note 176 at 1302 (RN 37).
180 Kelsen (1979) supra note 8 at 178–179 (Ch 57 XIII).
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