New Technologies in International Law / Tymofeyeva, Crhák et al.

Following up on the example of assistance to guerillas and other groups distinguished from the State in question, this may easily be performed with a striking resemblance in the cyber context. Providing groups of so-called hacktivists with malware, ransomware, etc. and/or training them in the usage against an enemy State would per analogiam constitute an infringement of the prohibition by the assisting State. Needless to say, that the mere financing of such groups without any other significant contribution would not amount to such a violation. 614 Taking a step back to the issue of qualification of situations acknowledgeable as the use of force in international law, there are some conditions set by the ICJ in its previous case law, that could serve as an instructive guideline. For the determination of an armed attack, another crucial term of art setting the required threshold in the modern self defense regulation, in Nicaragua the ICJ again made use of the Declaration on Friendly Relations and differentiated the most grave forms of the use of force constituting an armed attack from other less grave forms. 615 This position was subsequently refused by the United States, which articulated a position, later embraced by some parts of the scholarship, opposing any discretion between the levels of use of force and armed attacks. 616 Nevertheless, the preponderant part of the international community stands behind the distinctive conception, that leads to a simple conclusion of a minori ad maius – any armed attack constitutes the use of force, whereas the use of force does not qualify as an armed attack does not have any universal definition within the case law, binding normative documents or customary international law. 617 Although not being precisely defined, the distinction bears an important value in prescribing the boundary between a lawful reaction involving the recourse to force in self-defense to an armed attack in comparison to a reaction not involving any use of force to a less-intensity use of force by the initiator. At this point, the Tallinn Manual comes with a proposition of a set of eight suggested factors derived from an earlier original conception by its editor and the leading figure of the Tallinn process, prof. Michael Schmitt. 618 The following criteria are claimed to be designed to identify cyber operations correspondent to acts traditionally qualifiable as use of force, kinetic or non-kinetic in its nature. 619 The factors, as a progressive element 614 Schmitt M, Tallinn Manual on the International Law Applicable to Cyber Warfare (CUP, 2013), p. 48; Schmitt M, Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations (CUP, 2017), p. 332. 615 ICJ, Case Concerning Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States of America) , Judgment [1986] ICJ Rep 1986, para 191. 616 United States Department of Defence Law Manual (June 2015, Updated July 2023), pp. 47–48, para 1.11.5.2. Based inter alia on: Sofaer AD, ‘The Sixth Annual Waldemar A. Solf Lecture in International Law: Terrorism, the Law, and the National Defense’ (1989) 126 Mil L Rev 89, pp. 92-93 (1989); Taft WH IV, ‘Self-Defense and the Oil Platforms Decision’ (2004) 29 Yale J Int’l L 295, pp. 300–301 (2004). 617 See e.g., Focarelli C, ‘Self-Defence in Cyberspace’ in Research Handbook on International Law and Cyberspace (Elgar, 2021), p. 328 and following. 618 Schmitt M, ‘Computer Network Attack and the Use of Force in International Law: Thoughts on a Normative Framework’ (1999) 37 Colum J Transnat’l L 885, p. 914. 619 Schmitt M, Tallinn Manual on the International Law Applicable to Cyber Warfare (CUP, 2013), p. 49 and following; Schmitt M, Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations (CUP, 2017), p. 334 and following.

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