NATO Cooperative Cyber Defence Centre of Excellence: “The Tallinn Manual on the International Law Applicable to Cyber Warfare, written at the invitation of the Centre by an independent ‘International Group of Experts’, is the result of a three-year effort to examine how extant international legal norms apply to this ‘new’ form of warfare. The Tallinn Manual pays particular attention to the jus ad bellum, the international law governing the resort to force by States as an instrument of their national policy, and the jus in bello, the international law regulating the conduct of armed conflict (also labelled the law of war, the law of armed conflict, or international humanitarian law). Related bodies of international law, such as the law of State responsibility, are dealt with in the context of these topics. The Tallinn Manual is not an official document, but instead an expression of the scholarly opinions of a group of independent experts acting solely in their personal capacity. It is not meant to represent the views of the Centre, our Sponsoring Nations, or NATO; NATO doctrine; or the official position of any organization or State that provided observers to the project. The Tallinn Manual is available in both paper and electronic copies from Cambridge University Press (© Cambridge University Press 2013). We have also made the book available for reading and research.”