CYIL vol. 12 (2021)

CYIL 12 (2021) PREEMPTIVE SELF-DEFENCE IN CYBERSPACE The Court further refers to the UN General Assembly Resolution 3314 (XXIX) providing an exemplary enumeration of actions qualified as an “armed attack”. Similarly, the Court notes: “The exercise of the right of collective self-defence presupposes that an armed attack has occurred; and it is evident that it is the victim State, being the most directly aware of that fact, which is likely to draw general attention to its plight.” 22 In the same vein, State practice does not reveal any cases that States would argue via Art. 51 and reinterpret the very meaning of the terms “if an armed attack occurs”. Max Planck Encyclopedia of Public International Law notes accordingly: “It is generally considered that, for a resort to force to constitute a lawful exercise of the right of self-defence, it must meet the following conditions: i) it must be a response to an armed attack; ii) the use of force, and the degree of force used, must be necessary and proportionate; and iii) it must be reported to the Security Council […].” 23 Similarly, Salmon Dictionary dismisses the argument of preemptive self-defence while stressing it is “rejected by a vast majority of States and the doctrine”. 24 It reminds that Art. 51 stipulates that self-defence can only be resorted to in case of an armed attack, not a threat of an armed attack, in contrast to Art. 2 (4) which prohibits both threat and use of force. Moreover, the concept of preemptive self-defence is incompatible with the condition of proportionality. The only question relevant to this provision is the moment of activation of self-defence in reaction to an armed attack which has already been launched but has not attained the target yet – does the key term “occur” means “launch” or the “hit” and the coincident causation of destructive effects? Max Planck Encyclopedia of Public International Law remarks that “[i]t is generally accepted that an armed attack may occur before the victim sustains any casualties or suffers any damage – the contrary view confuses the attack with the effects of the attack; as a matter of logic, the former must precede the latter” 25 . In the conventional warfare, the time lapse between the launch of the attack and the very “hit” might, indeed, be possibly considerate and give rise to various legal assessments – is the setting sail of a military fleet from State A aiming to carry on a blockade of the ports and coasts of a nearby State B qualified as an armed attack or only the very exercise of the blockade is defined so? Is there a difference if the navigation takes an hour or three days? What about the take-off of an aircraft aiming to bomb a foreign territory? Max Planck Encyclopedia notes quite pertinently in this respect that the result of this uncertainty is that “some commentators who reject the notion of anticipatory or preemptive self-defence adopt an approach to the question of when an armed attack begins which means that their application of the law of self-defence to the facts of many cases is very close to that of the proponents of some variations of the anticipatory self-defence theory” 26 . In all cases, a preparation of an armed attack is not qualified as an armed attack. It is possible to note, reasonably, that if the initial phase of an armed attack (launch of the missile, taking off the plane, setting off the invasion by a foreign uniformed army etc.), which 22 Ibid ., § 232. 23 Greenwood, Ch., Self-Defence, April 2011. In: Peters, A., Wolfrum, R. (eds.), Max Planck encyclopedia of public international law . Oxford University Press, available at , para. 8. 24 Salmon, J. (dir.), Dictionnaire de droit international public , Bruxelles, p. 642 (author’s translation). 25 Greenwood, op. cit. note 23, para. 42. 26 Ibid .

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