CYIL vol. 12 (2021)

CYIL 12 (2021) PREEMPTIVE SELF-DEFENCE IN CYBERSPACE construction is inverse in a sense that a cyberoperation perpetrated by non-State actors which cannot be attributed, directly or indirectly, to State can’t be qualified, according to France in line with ICJ case law, as an armed attack. France admits however that a “general practice may shift towards [such] an interpretation of the law of self-defence” but “any such development will have to be made bearing in mind the Rome Statute of the International Criminal Court (ICC) as amended in 2010 to add the crime of aggression”. 70 For the moment, no State expressly claimed the right to self-defence or preemptive self-defence in cyberspace in reaction to a cyberattack committed by an individual not attributable to a sovereign State. 71 Sexto , and essentially, how to define the imminence of a cyberattack? – an evergreen challenge linked to preemption in general and not answered yet satisfactorily, aiming to evade a subjective discretion and potential of abuse by a State. 72 Whether cyberspace provides a more targeted and exclusive perspective accepted by the international community as a whole will be shown by State practice. For the moment, the absence of State practice and no precision by the proponents leaves the question open. An interesting doctrinal idea, albeit, likewise, not deprived of the potential of abuse, views the aspect of imminency as a combination of the temporal proximity to the prospective armed attack and the “last feasible window of opportunity” standard. 73 The latter refers to the right of a State to “act in anticipatory self-defence against an armed attack […] when the attacker is clearly committed to launching an armed attack and the victim State will lose its opportunity to effectively defend itself unless it acts” 74 . Finally, the overarching challenge in the cyberspace is for now its largely covert, confidential and non-transparent sphere, a multilayered zone of operation both of diverse non-State actors and State authorities and intelligence. Any evidence and public justification necessary for the emergence of an international custom might be thus more difficult and dissimulated. These are the questions to be raised in the follow-up to the claims to the right to preemptive self-defence in cyberspace both by the proponents and all other States who hold the scepter of a formulation of a new international customary rule. Conclusion Public international law is not immutable, quite the opposite. It is a fine example of ensemble of norms that via its intrinsic and dynamic processes reacts appropriately to new challenges on the international level and threats to peace and security. The prerequisite is, however, the respect for fundamental rules, including the core procedural guarantees. The principle of sovereign equality of States, the basics of norm-making, and values of international community as a whole are at the center. Any new rule can be standardized by 70 Ibid. , p. 9. 71 Finland, while affirming that “[t]he right of self-defence arises if a cyberattack comparable to an armed attack occurs and can be attributed to a particular State”, notes: “While the possibility of a cyberattack rising to the level of an armed attack without the involvement of any State is conceivable, the related questions of self-defence against non-State actors are too complicated to be discussed here”, International law and cyberspace , op. cit. note 12, p. 7 and note 24. Some commentators raise this option, see WILMSHURST, E., op. cit. note 43. 72 See the reflection on this topic, for example, in CASSESE, A., op. cit., note 38, and in WILMSHURST, E., ibid ., pp. 8 et s . 73 Tallinn Manual , op. cit. note 18, p. 352. 74 Ibid ., p. 351.

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