CYIL vol. 9 (2018)

CYIL 9 ȍ2018Ȏ

INTERNATIONAL LAW ON THE USE OF FORCE…

4.1 Character of Practice The practice, to be relevant, must be qualified . The first aspect to be assessed here is alleged longevity of the practice ( usus longaevus ). In 2018, an opinion that existence of customary international law necessitates immemorial usage (practice) sounds like voice of prehistory and clearly is unsustainable. 36 Quite contrary, as confirmed by the ICJ, a relatively short period in which a practice is followed is not, in and of itself, an obstacle to determining that a corresponding rule of customary international law exists. 37 Higher intensity of an international life, activity of international organizations, better means of communication and various other factors accelerated formation of customary international law. At the same time, authors refer to opinion of the ILC according to which there is no such thing as ‘instant custom’, 38 despite the fact it gained some support among scholars. 39 This latter approach is too excessive as there always must be some time elapsed for rule of customary international law to emerge. Case-law of the ICJ and current work of the ILC support position presented by Corten that “even if [the formation of customary international law] can be rapid, it is difficult to conceive of the development of custom as instantaneous.” 40 In this respect, authors of present contribution stand somewhere in the middle between restrictive and extensive approach: 41 custom evolves gradually nevertheless its formation might be relatively rapid, but never instant. Obviously, it is not possible to specify sufficient (required) time to elapse for customary international law to emerge. At this stage, it is possible only to use argument quid pro quo as a certain hint. In the line with the ICJ, there is an indirect proportion between duration of practice and its extensiveness and uniformity – “within the period in question, short though it might be, State practice, including that of States whose interests are specially affected, should have been both extensive and virtually uniform”. 42 The practice must be general, as the ILC explained it means that the practice must be sufficiently widespread and representative, as well as consistent. 43 Rules concerning prohibition on the use of force are part of ius cogens , even though there are some marginal doctrinal opinions contesting this widely accepted position. 44 According to Article 53 of the VCLT, peremptory norm is a norm of general international law, therefore practice of all and not only major (powerful) States must be taken into account. The argument is often presented, employing reference to the work of the ICJ quoted in the previous paragraph, that a particular weight 36 Jurisdiction of the European Commission of the Danube , PCIJ, Advisory opinion, 8 th December 1927, Dissenting Opinion by M. Negulesco, p. 105. The teachings of publicists and of international practice agree in recognizing the necessity of immemorial usage consisting both of an uninterrupted recurrence of accomplished facts in the sphere of international relations and of ideas of justice common to the participating States and based upon the mutual conviction that the recurrence of these facts is the result of a compulsory rule. 37 North Sea Continental Shelf , Judgment, I.C.J. Reports 1969, p. 43, para. 74. 38 ILC, A/71/10, p. 96, para. 9. 39 Originally, the instant custom theory was introduced by B. Cheng in 1965. Cf. CHENG, B.: United Nations Resolutions on Outer Space: “Instant” International Customary Law? Indian Journal of International Law . 1965, vol. 5, pp. 23-48. For other references cf. SCHARF, M.: Customary International Law in Times of Fundamental Change. Recognizing Grotian Moments . Cambridge: CUP, 2013, pp. 8-9. 40 CORTEN, O.: supra 2006, p. 818. 41 Ibid , p. 804. 42 North Sea Continental Shelf , Judgment, I.C.J. Reports 1969, p. 43, para. 74. 43 ILC, A/71/10, p. 94. 44 GREEN, J. A.: Questioning the Peremptory Status of the Prohibition of the Use of Force. Michigan Journal of International Law . 2011, vol. 21, issue 3, pp. 215-257.

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