18. In Ireland’s view, a cyber-operation attributable to a state will amount to a use of force if its scale and effects correspond to those of a physical use of force. This may include instances where a cyber-operation does not cause physical damage, such as where there is significant impairment of functionality of critical infrastructure. It is recalled that treaties, including the UN Charter, must be interpreted in the light of their object and purpose.15 Although present day technology and our heavily digitised world may not have been contemplated at the time of the adoption of the Charter, it is appropriate to interpret Article 2(4) as applying to force emanating from cyber operations, notwithstanding the fact that the traditional physical or kinetic element may be lacking in terms of both means and impact. 19. For completeness, it is noted that a cyber-operation that falls below the threshold of use of force might nonetheless constitute an unlawful intervention in the internal affairs of a state or a violation of its sovereignty. Moreover, not every use of force contrary to Article 2(4) will amount to an “armed attack” within the meaning of Article 51 of the UN Charter (this is considered further under the heading of self-defence, below). Legal Attribution 20. It is an established principle of international law that every internationally wrongful act of a state entails responsibility. As set out in the International Law Commission’s Draft Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), there is an internationally wrongful act of a state when conduct consisting of an action or omission: first, is attributable to the state under international law; and secondly, constitutes a breach of an international obligation of the state.16 While the ARSIWA are not legally binding, in most respects they are widely accepted as largely reflecting customary international law. Absent any rules constituting lex specialis, the general rules of state responsibility apply in the cyber context. 21. In customary international law, attribution of an internationally wrongful act to a state can arise in several situations including: acts of organs or officials of the state; ultra vires acts; acts of individuals if conduct is directed and controlled by the state; and acts of individuals whose conduct has been acknowledged or adopted by the state.17 The last two scenarios are arguably the most relevant in the context of cyberspace, as the nature of cyber-operations means that they can be very difficult to attribute to a specific state organ or official directly. 22. In relation to the concepts of direction and control, in the Nicaragua case the ICJ determined that responsibility for the actions of a third party arose where there was “effective control of the military or paramilitary operations in the course of which the 15 1969 Vienna Convention on the Law of Treaties, Article 31. Article 2 ARSIWA. 17 See Articles 4 to 11 ARSIWA 16