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

5.2 T he L imits to the U se of F orce

in C yberspace : T he T allinn M anual P erspective

By Marek Gerle and Adam Crhák (Charles University)

Introduction The concept of the use of force has represented one of the cornerstones of modern international law and served as the base of the post-WWII security architecture for more than seven decades now. The contemporary ius ad bellum, petrified by the UN Charter and later elaborated in different ICJ cases, stands as a solid body of law regulating the resort to force in international relations. But what if the reality of the 21 st century surpassed the traditional concept and new cyber means of warfare were employed? The 2007 cyber-attacks on Estonia and the Russo-Georgian war a year later reinvigorated the focus of international legal scholarship on this peculiar subject. The Tallinn Manual, as well as its version 2.0 (and soon-to-come 3.0), came into existence due to the newly felt urgency of the upgraded shape of modern warfare. To this day, the project represents the most comprehensive attempt to depict the current state of normativity regulating the use of force with regards to cyberspace. Ever since the publication of its first volume, the Manual has elicited a considerable number of various reactions from concurrent legal scholars and States representatives alike. The aim of this article is to present an analysis of its stance towards the use of force in the digital sphere as well as the reactions and evaluations from relevant stakeholders. The ultimate objective is to shed light on the normative quality of the Manual and its potential of becoming an expression of binding principles and rules of the prospective international law. Has the Manual become too influential to be disregarded in relation to the future conception and codification of normativity of the ius ad bellum in cyberspace? Due to the limitations of the given format, the paper will concentrate on the notions of the use of force, armed attack and the possible attribution of the given acts. Questions of the collective form of self-defense and actions under the Chapter VII of the UN Charter will not be dealt with in detail. 1. The use of force in cyberspace As in other fields of the law, the inherent abstractness of normativity concerning the use of force does not prevent the regulation from advancing, yet on the contrary it allows it to develop regarding new challenges. In its far-reaching advisory opinion on the Legality of Nuclear Weapons , the ICJ observed that the relevant provisions of the UN Charter applied to any use of force, regardless of the weapons employed. 607 In conformity with this stance, even the cutting-edge cyber-technologies, when used in an equivalent manner as traditional weapons, could fall under the legal regime of the art. 2 (4) of the

607 ICJ, Legality of the Threat of Use of Nuclear Wapons, Advisory Opinion [1996] ICJ Rep 1996, para 39.

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