CYIL vol. 11 (2020)

SILVANO DENEGA SOUZA CYIL 11 (2020) It is convenient to clarify that the application of lex specialis could appear in two distinct scenarios: that of a supervening private norm with enforcement effect of a general rule, or the case of a private rule which modifies, revokes, derogates or abrogates an existing general rule. 15 Following the same rationale, the International Court of Justice has conveniently made use of the expression in its decision on the Gabčíkovo-Nagymaros Project case (Hungary v. Slovakia). In the 1997 judgment, the Court ruled: § 132 […] it is of cardinal importance that the Court has found that the 1977 Treaty is still in force and consequently governs the relationship between the Parties. That relationship is also determined by the rules of other relevant conventions to which the two States are party, by the rules of general international law and, in this particular case, by the rules of State responsibility; but it is governed, above all, by the applicable rules of the 1977 Treaty as a lex specialis . 16 Nonetheless, it was in the eighty’s (1980’s), most specifically in the Tehran Hostages case, that the International Court of Justice firstly brought the concept of self-contained regimes for the first time on an official report. At that time the Court stated as follows: […] diplomatic law provides the necessary means of defence against, and sanction for, illicit activities by members of diplomatic and consular missions. …The rules of diplomatic law, in short, constitute a self-contained regime which, on the one hand, lays down the receiving State’s obligations regarding the facilities, privileges and immunities to be accorded to diplomatic missions and, on the other, foresees their possible abuse by members of the mission and specifies the means at the disposal of the receiving state to counter any such abuse. The means are by their nature entirely efficacious 17 . The importance of the ILC’s recognition of the existence of a lex specialis which derogates legi generali is the foundation for the legitimization of fragmentation. In this sense, a more specific norm of environmental law will have precedence over those usually associated with general international law, and this latter, when dealing with relevant environmental issues, shall trust its application to the most specialized norm, reserving the peculiar status of a proper, fragmented, self-contained regime . A particular approach of the ILC on self-contained regimes is but another important matter raised in the mentioned report. The conclusion of the members of the Commission followed the incontrovertible emergence of new kinds of specialized law, the main goal of which is to technically respond to the ‘growing concern over the state of the international environment’ 18 and this on the basis of functional requirements. After the recognition of the existence of specialized regimes, the ILC has only reasserted a reality, which is the operation of certain currently fragmented areas, originally from general international law possessing (specific) pre-established objects, their own rights and duties,

15 Except for norms enjoying jus cogens status. 16 Gabčíkovo-Nagymaros Project (Hungary v Slovakia) (Judgment of 25 September 1997) [1997] ICJ Rep 1997, 76

(italic emphasis in the original, bold emphasis added). 17 International Court of Justice Report (1980), 38. 18 International Law Commission (n 11) 12.

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