2019 - SUPPLEMENT TO AUSTRALIA’S POSITION ON THE APPLICATION OF INTERNATIONAL LAW TO STATE CONDUCT IN CYBERSPACE In the International Cyber Engagement Strategy (2017) (Strategy), Australia committed to periodically publish its position on the application of relevant international law to state conduct in cyberspace. The first such publication appeared in Annex A to the Strategy. This document is the second publication and is aimed at further elaborating Australia’s position on applicable international law as expressed in the Strategy. As such, it should be read as a supplement to that document. Application and development of international law The Strategy recognised the well-established position that existing international law - including the UN Charter in its entirety - provides the framework for responsible state behaviour in cyberspace. The international community, including the permanent members of the United Nations (UN) Security Council recognised this in the 2013 and 2015 reports of the UN Group of Governmental Experts on the use of Information Communications Technologies in the Context of International Security (UNGGE), as adopted by the UN General Assembly. Australia also acknowledged that activities conducted in cyberspace raise new challenges for how international law applies. To deepen understandings and set clear expectations, Australia encourages states to be transparent in how they interpret existing international law as it applies to state conduct in cyberspace. The Strategy, and this supplement, form part of Australia’s ongoing effort to make its views on the applicability of international law public. The law on the use of force (jus ad bellum) and the principle of non-intervention The United Nations Charter (Charter) and associated rules of customary international law apply to activities conducted in cyberspace. Article 2(3) of the Charter requires states to seek the peaceful settlement of disputes and Article 2(4) prohibits the threat or use of force by a state against the territorial integrity or political independence of another state, or in any manner inconsistent with the purposes of the UN. In the Strategy, Australia made clear that these obligations – and the UN Charter in its entirety, including those obligations, apply in cyberspace as they do in the physical realm. A use of force will be lawful when the territorial state consents, it is authorised by the Security Council under Chapter VII of the UN Charter or when it is taken pursuant to a state’s inherent right of individual or collective self-defence in response to an armed attack, as recognised in Article 51 of the Charter. Australia considers that the thresholds and limitations governing the exercise of self-defence under Article 51 apply in respect of cyber operations that constitute an armed attack and in respect of acts of self- defence that are carried out by cyber means. Thus if a cyber operation – alone or in combination with a physical operation – results in, or presents an imminent threat of, damage equivalent to a traditional armed attack, then the inherent right to self-defence is engaged. The rapidity of cyber attacks, as well as their potentially concealed and/or indiscriminate character, raises new challenges for the application of established principles. These challenges have been raised by Australia in explaining its position on the concept of imminence and the right of self-defence in the context of national security threats that have evolved as a result of technological advances (see Figure 1). www.dfat.gov.au/cyberaffairs esafety.gov.au/parents