CYIL vol. 8 (2017)

CYIL 8 ȍ2017Ȏ FAILURE TO REACT AS EVIDENCE OF OPINIO IURIS As mentioned above, according to the Commission’s commentary, the circumstances “call for some reaction”, for example, where the practice is one that - directly or indirectly 9 – affects (usually unfavourably) the interests or rights of the State failing or refusing to act; in addition, certain practice may be seen as affecting all or virtually all States. 10 On the other hand, some commentators, cited by the Special Rapporteur in his Third report on identification of customary international law, assert that silence can be considered to be tacit recognition of a customary norm when “an emerging rule affects the interests of a particular State”, 11 or when a “concrete action taken by a State in a specific case … has an immediate impact on the interests of another State”. 12 Also the Encyclopedia of Public International Law cited above puts emphasis on the abstention from reaction by “States particularly interested, concerned and affected” by relevant practice. In addition, the Special Rapporteur himself mentioned, in his Third report, that “there could be various reasons for a refusal or failure to act, including a lack of capacity to do so or a lack of direct interest …”. 13 Other authors, cited in the Third report by the Special Rapporteur, suggest that “ acquiescence must be based upon full knowledge of the [alleged] rule involved … [w]here a failure to take a course of action is in some way connected or influenced or accompanied by a lack of knowledge of all the relevant circumstances, then it cannot be interpreted as acquiescence”; 14 that “passive conduct could only amount to qualified silence if a State knows of the practice of other States and of the (emerging) customary rule ”; 15 and that “ [m]ere toleration is not the same as acceptance of practice as law ” since “[t]here are implications for the doctrine of acquiescence, the burden of proof for which is very high, presupposing long and consistent inaction accompanied by consciousness of legal change ”. 16 9 In this regard, the Special Rapporteur referred, in his Third report on identification of customary international law, to DANILENKO, G.M., Law-Making in the International Community (Martinus Nijhoff Publishers, 1993), p. 108 (“Under existing international law, absence of protests implies acquiescence only if practice affects interests and rights of an inactive state … As a rule, not only direct but also indirect interests may be taken into account”); cited in: Third report, op. cit. sub 4, p. 13, fn. 50. 10 Special rapporteur refers again to DANILENKO, G.M., Law-Making in the International Community (Martinus Nijhoff Publishers, 1993), p. 108; cited in: Third report on identification of customary international law, pp. 12-13, fn. 51 “[i]n areas of relations affecting the common interests of all mankind the presence of a general interest of all states may give sufficient grounds for assuming that absence of protests implies acquiescence”. 11 TUNKIN, G. I., (SHESTAKOV, L. N. ed., BUTLER, W. E. ed., trans.), Theory of International Law (Wildy, Simmonds & Hill, 2003), at p. 139; cited in: Third report on identification of customary international law, op. cit. sub 4, p. 13, fn. 50; emphasis added by the author of the present article. 12 AKEHURST, M., “Custom as a Source of International Law”, British Yearbook of International Law , 47 (1977), p. 40; cited in: Third report on identification of customary international law, op. cit. sub 4, p. 13, fn. 50; emphasis added by the author of the present article. 13 Third report on identification of customary international law, op. cit. sub 4, p. 11, para 22. 14 SHAW, M. N., International Law , 7th edition (Cambridge University Press, 2014), p. 58; cited in: Third report on identification of customary international law, op. cit. sub 4, p. 13, fn. 52; emphasis added by the author of the present article. 15 VILLIGER, M. E., Customary International Law and Treaties , 2nd edition (Kluwer Law International, 1997), p. 39; cited in: Third report on identification of customary international law, op. cit. sub 4, p. 13, fn. 52; emphasis added by the author of the present article. 16 ORAKHELASHVILI, A., The Interpretation of Acts and Rules in Public International Law (Oxford University Press, 2008), at p. 94; cited in: Third report on identification of customary international law, op. cit. sub 4, p. 14, fn. 53; emphasis added by the author of the present article.

111