Denmark's Position Paper on the Application of International Law in Cyberspace: Introduction.

A State may be responsible under international law for acts undertaken by an organ of the State or by actors exercising government authority on behalf of that State. Denmark does not share this view, but contends that State practice supports that a State might in some instances and under certain conditions be permitted to exercise self-defence against an armed attack by a non-State actor. 2 Sovereignty Sovereignty denotes each State's authority to exercise within its territory the functions of a State, to the exclusion of any other State. Countermeasures must be directed against State organs or other entities acting on behalf of, or whose acts are attributable to, a State as it is the State that is in breach of its obligations vis-à-vis the target State. [Extracted from the article]