The Tallinn Manuals and the Making of the International Law on Cyber Operations

The Tallinn Manuals (the Manuals) attempted to clarify how to apply existing international law to cyber operations. Though the Manuals are non-binding instruments, the Group of International Experts claimed that they reflected the lex lata applicable to cyber operations. However, this claim is questionable due to the dominating role of a few Western states in the drafting process and the linked neglect of the practice of “affected states” in cyber operations. This article examines the quality of the Manuals’ drafting process and the composition and impartiality of the experts involved. It focuses on the issue of the prohibition of the use of force. The aim of this examination is not to discuss whether the Manuals provided the right answer to the question of how international law applies to cyber operations. Rather, they function as a case study of how legal scholarship may affect the making of international law. The article concludes that certain rules in the Manuals are marked by NATO influence and overlook the practice of other states engaged in cyber operations. Therefore, the Manuals disregard the generality of state practice, which should be the decisive factor in the formation of customary international law. As far as “political activism” may be involved, the article argues that the role of legal scholars as assistants to the cognition of international law could be compromised.