World Wide Warfare - 'Jus Ad Bellum' and the Use of Cyber Force

Abstract:     
The jus ad bellum rules contained in the UN Charter seem to be flexible enough to be extended to warfare that did not exist when they were conceived, i.e. cyber warfare. The main question is whether a cyber attack is an action below the threshold of the use of force, or a use of force, or a use of force amounting to an armed attack. This article concludes that cyber force can be qualified as a use of ‘armed’ force in the sense of Article 2 (4). On the other hand, only large scale cyber attacks on critical infrastructures that result in significant physical damage or human losses comparable to those of an armed attack with conventional weapons would entitle the victim state to invoke self-defence under Article 51 of the UN Charter. Self-defence would also be possible against a cyber attack that does not reach the threshold of an armed attack but which prepares an imminent armed attack with conventional weapons (although only if the Caroline requirements are met). The absence of frontiers in cyberspace and the possibility for the perpetrators to hide behind botnets or IP spoofing, however, could hamper the identification of the origin of the cyber attack and the application of the law of state responsibility.

This article also suggests that customary international law could play a role in this area, as there is already some relevant state practice and opinio juris, in particular with regard to the right to self-defence against cyber attacks. Although this might lead to the formation of a customary rule in the upcoming years, the process is on-going and, considering the ambiguity of the positions of certain states and international organisations, it is still difficult to predict its outcome.

Number of Pages in PDF File: 46

Keywords: Cyber warfare, cyber force, cyber attack, jus ad bellum, United Nations Charter, self-defence, state responsibility

JEL Classification: K33

Accepted Paper Series