This article explores the nature, formation and evolution of international legal norms pertaining to cyber activities. At present, this category of norms operates in the shadow of most others, a situation often attributed to the alleged paucity of international law applicable in cyberspace. A frequent topic among states as well as in the academia is if and to what extent cyber activities necessitate new international law. To answer this question, an understanding of how international law is created or evolves is paramount.
In this Tallinn Paper, Professor Michael Schmitt, the Centre’s Senior Fellow, and Liis Vihul, Researcher in the Law and Policy Branch at the Centre, discuss the two sources of international law – treaties and custom – and explain the different challenges cyberspace poses to their formation, identification and application.