The application of international law in cyberspace 7. Costa Rica believes that existing international law applies in its entirety to ICTs, just as it does to all other technologies.5 With regard to the prohibition on the use of force and the rules of international humanitarian law, the International Court of Justice (ICJ) has held that these rules apply ‘to all forms of warfare and to all kinds of weapons, those of the past, those of the present and those of the future’.6 The same logic applies to the entirety of international law: as a matter of principle, it is applicable to all forms of human activity, whether they involve new technologies or not. 8. Existing international law applies to and governs the use of ICTs by State and non-State actors. Cyber-specific State practice and opinio juris can be useful in fleshing out how international law applies to ICTs and may eventually develop the law in this context. In the same vein, the non-binding, voluntary norms of responsible State behavior in cyberspace, articulated by the GGE and OEWG, do not replace, but are complementary to existing international law in the cyber context.7 9. Accordingly, it is emphasized the relevance of strengthening and improvement of international cooperation guided by international law in cyberspace, as a global public good. State responsibility 10. Costa Rica believes that, under customary international law, as codified in Articles 1 and 2 of the International Law Commission (ILC)’s Articles on Responsibility of States for Internationally Wrongful Acts (‘the ILC Articles’),8 cyber operations may amount to internationally wrongful acts engaging the responsibility of a State when they can be attributed to it and involve a breach of its international obligation(s). 11. In Costa Rica’s view, the existing customary thresholds for legal attribution of conduct to States continue to apply in cyberspace.9 Thus, cyber operations can only be attributed to a State when they are carried out by, inter alia, i) State organs,10 including persons or groups under complete dependence on the State,11 ii) persons or entities empowered by law to exercise elements of governmental authority,12 including organs placed at the disposal of 5 See, e.g., GGE 2015 Report (n 1), para. 24; OEWG Final Substantive Report (n 1), para. 34. Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 ICJ 226 Rep (‘Nuclear Weapons case’), paras 39, 85–86. 7 OEWG Final Substantive Report (n 1), para. 25. 8 ILC, ‘Responsibility of States for Internationally Wrongful Acts’, UNGA Res. 56/83, 12 December 2001, corrected by A/56/49(Vol. I)/Corr.4 (‘ILC Articles’). 9 Articles 4-11, ILC Articles (n 8). 10 Article 4, ILC Articles (n 8). 11 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America), Judgment, 1986 ICJ Reports 14 (‘Nicaragua case’), paras 109–110. 12 Article 5, ILC Articles (n 8). 6 3