CYIL vol. 13 (2022)

JAKUB SPÁČIL CYIL 13 ȍ2022Ȏ characteristics of an armed attack if the “scale and effects” of cyber operations correspond to the “scale and effects” of kinetic operations. 3 However, is such a solution appropriate, does it correspond to state practice and is it consistent with the objectives and purposes of the UN Charter? Is it really sufficient to rely on the “scale and effects” of the cyber operation (objective elements) or should the intent of the originating State (subjective element) also be taken into account? Answering these questions, which have so far been at the very margins of international legal discourse, 4 is the aim of this paper. Before proceeding to the actual subject of this article, it is first necessary to establish a few basic facts. Cyberspace has become another domain in which states conduct military operations. It has thus ranked alongside land, sea, air and space. 5 And like the original four domains, conduct in cyberspace is regulated by international law. 6 One rule of international law applicable in cyberspace is the prohibition on the use of force and the related exceptions to that prohibition. 7 There is general agreement on the existence of two exceptions to this prohibition: the authorization of the UN Security Council and the use of force in self defense. The permissibility of the use of force in self-defense against a cyber operation and the limits of this right are currently the subject of scholarly debate and this article aims to contribute to this debate. Animus aggressionis as a subjective element of an armed attack The customary right of self-defence is codified in Article 51 of the UN Charter, which defines it as follows: ‘Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations…’. Thus, an obvious prerequisite for the use of force in self-defense is the existence of an armed attack. 8 The International Court of Justice (ICJ), in the seminal judgment Nicaragua v. United States of America, held that “it will be necessary to distinguish the most grave forms of the use of force (those constituting an armed attack) from other less grave forms”. 9 The ICJ’s decision therefore implies that only the most serious uses of force 4 References to animus aggressionis in the context of cyber operations can be found in a number of scholarly publications, but always only in similarly brief mentions without deeper analysis. See e. g. WAXMAN, C. M. Cyber-Attacks and the Use of Force: Back to the Future of Article 2(4). The Yale Journal of International Law , 2011, vol. 36, p. 445; NGUYEN, 2013, p. 1122, see supra note 2; ROSCINI, M. Cyber Operations and the Use of Force in International Law. 1st ed. New York: Oxford University Press, 2016, p. 76; SIMMONS, N. A Brave New World: Applying the International Law of War to Cyber-Attacks. Journal of Law & Cyber Warfare , 2014, vol. 4, no. 1, p. 81. 5 VON HEINEGG, W. H. Territorial Sovereignty and Neutrality in Cyberspace. International Law Studies , 2013, vol. 89, p. 123. 6 United Nations. Report of the Group of Governmental Experts on Developments in the Field of Information and Telecommunications in the Context of International Security [online]. UN Doc. A/68/98*. 24 June 2013 [accessed 13 March 2022], p. 8, para. 19. Available at < https://documents-dds-ny.un.org/doc/UNDOC/GEN/ N13/371/66/PDF/N1337166.pdf?OpenElement>. 7 See Charter of the United Nations, art. 2 (4). 8 A discussion of anticipatory self-defense is beyond the scope of this paper. For more information on the topic see e.g. TITIRIGA, R. Cyber-attacks and International Law of Armed Conflicts a “jus ad bellum” perspective. Journal of International Commercial Law and Technology , 2013, vol. 8, no. 3, pp. 184-186. 9 International Court of Justice, Judgment of 27 June 1986, Case Concerning Military and Paramilitary Activities 3 SCHMITT, M. N. et al. Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations. 2nd ed. Cambridge: Cambridge University Press, 2017, p. 344.

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