Nation-State Cyber Operations Legal Considerations: An Estonian Case Study

States use cyberspace as one of the platforms for pursuing national interests, also in the context of armed conflict. Due to their inherent purpose, certain principles of international law also apply to the activities of entities (state and non-state) in cyberspace. The main research problem was defined as the following question: under what conditions could the terms in international law be used to describe the events in Estonia in 2007 that imply the possibility of eventual responses or demands by victim parties consistent with international standards? In the article, the events in Estonia in 2007 were compared to existing methods of cyber warfare. The main research methods that were used to achieve the essential objective were: analysis of legal documents and critical analysis of the literature on the subject. The analysis is interdisciplinary in nature and will be particularly useful to researchers of international political and/or military relations and those interested in aspects of international security.