Abstract

The 21st century has witnessed the rapid emergence of cyber technologies worldwide. The Internet has dramatically gone beyond the physical boundary of each state, making cybersecurity a challenge facing the international community as a whole. Among the various international systems, international law plays a significant role and functions irreplaceably in addressing these challenges. However, it remains a question whether the regulatory framework of current international law is well equipped for the challenges deriving from cyberspace. As a response to this question, this article will particularly look to the law of war, which inquires about the legitimacy of the acts conducted under Jus in Bello (known as “international humanitarian law” or “law of armed conflict”), and Jus ad Bellum (known as “use of force”). Generally, Jus in Bello governs the conduct of warring parties, whereas Jus ad Bellum formulates the conditions for war. While there has been a relative abundance of scholarship exploring the applicability of Jus in Bello in the cyber sphere, less attention has been paid to the cyber implications of Jus ad Bellum. Accordingly, this article will particularly focus on the interactions between cyber technology and Jus ad Bellum, primarily the “use of force” under the Charter of the United Nations (hereinafter “the U.N. Charter”). The U.N. Charter prohibits the illegal use of force, but recognizes two circumstances where the use of force is permissible. In terms of the illegitimate use of force, Art. 2(4) of the U.N. Charter stipulates that the threat or use of force is unjustifiable if it is “against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.” On the contrary, U.N. Charter Art. 51 and Art. 42 provide two justifications for the use of force. Specifically, Art. 51 recognizes the Member State’s “inherent right of individual or collective self-defense,” and Art. 42 legitimizes the use of force that adheres to the Security Council’s authorization. For this article, the following discussions will focus on two main issues: first, the controversies that arise from the scope of “use of force” under Art. 2(4) when it is applied within the cyber realm; second, the requirement of attribution under Art. 51 and its intersection with cyberspace. Instead of judging if specific acts conducted in cyberspace might fit into the U.N. Charter, the inquiry of this article is broader and more structural: are the current rules and interpretations of the U.N. Charter sufficient for making that determination?