CYIL vol. 13 (2022)

CYIL 13 ȍ2022Ȏ ANIMUS AGGRESSIONIS: THE ROLE OF INTENT IN THE ANALYSIS OF ARMED … constitute armed attacks. If the State concludes that it is entitled to use force in self-defense, the exercise of that right is then limited by two conditions arising from customary law, namely necessity and proportionality. 10 An armed attack within the meaning of Article 51 of the UN Charter includes not only kinetic attacks with conventional weapons, but can also be committed by cyber means. 11 The crucial question is how to determine which cyber operations fulfil the characteristics of an armed attack. In the state practice and in the academic literature, the doctrine of “scale and effects”, according to which an armed attack is a cyber operation that is comparable in scale and effects to a kinetic attack, i.e. that causes “injury, death, damage, or destruction” on the required scale, seems to be prevalent. 12 The “scale and effects” doctrine was developed by the ICJ in the Nicaragua case, when it used this criterion to separate lesser uses of force from armed attack (see above). Also, the Tallinn Manual 2.0 provides in Rule 71 that the determination of whether a cyber operation constitutes an armed attack depends “on its scale and effects”. 13 Of the available state positions on self-defense against cyber operations, reference to “scale and effects” appears in the positions of Estonia, Finland, Germany, New Zealand, Norway, Singapore and the United Kingdom. 14 An example of a cyber operation that would undoubtedly meet the characteristics of an armed attack under the “scale and effects” doctrine would be an attack on a computerised train control system resulting in a targeted train collision with serious material damage and loss of life. However, what role does the intent of the attacker to carry out an armed attack (also known as animus aggressionis , intent to hurt or hostile intent) play in the consideration of the fulfilment of the conditions of self-defense? 15 From the above, it would seem that the intent of the attacker plays no role. If one state carries out an operation against another state (whether by standard military means or by cyber means), the “scale and effects” of which can be objectively assessed as “the gravest form of use of force”, i.e., for example, the physical destruction of a power plant, according to the approach presented above, a self-defensive response could be taken without further ado. This conclusion was presented by several in and against Nicaragua (Nicaragua v. United States of America) , p. 101, para. 191 (hereinafter “Nicaragua v. United States”). 10 AKANDE, D., LIEFLÄNDER, T. Clarifying Necessity, Imminence, and Proportionality in the Law of Self Defense. American Journal of International Law , 2013, vol. 107, no. 3, pp. 563–570. 11 SCHMITT, 2017, p. 340, see supra note 3. 12 Ibid, p. 342. We leave aside cyber operations that cause non-material damage, where even these can fulfil the characteristics of an armed attack according to some authors. 13 Ibid, p. 339. Rule 71: “ A State that is the target of a cyber operation that rises to the level of an armed attack may exercise its inherent right of self-defence. Whether a cyber operation constitutes an armed attack depends on its scale and effects.“ 14 Among the states that explicitly mention the “scale and effects” doctrine are Estonia, Germany, Italy, the Netherlands, New Zealand, Norway, Singapore, Switzerland and the United Kingdom (see the list of state positions available at < https://cyberlaw.ccdcoe.org/wiki/Self-defensce> ). 15 Roscini defines animus aggressionis as “deliberate intention to cause damage to property, people or systems of a certain state”. See ROSCINI, 2016, p. 77, see supra note 4.

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