Cyber Espionage in International Law: Attribution of ng International Responsibility to States in a State of uncertainty

The rapid advancement of technology and the unique characteristics of cyberspace have caused change in many of international law's classic concepts, and in most cases the lack of coherent customary regimes prepared grounds for new interpretation of on classic concepts. Cyber espionage is a relatively new concept in international law, and there is no agreement on legal regime governing it. Ambiguity and fear of y extending principles and rules governing espionage in traditional sence, to the cyberspace, which is generally the domain of soft law practice, has put international law governing this new concept in a state of uncertainty. Therefore, on one hand, the legitimacy of extraterritorial infiltration acts of States through espionage remains controversial, and on the other hand, the use of virtual instruments by States for advancing their extraterritorial infiltration into cyberspace of other States, has fueled ambiguities. The lack of specific international customary and treaty obligations in this regard, paves the way for the application of general principles and rules of international law.This article seeks to elucidate the concept and scope of cyber espionage and the international responsibility arising from it, taking into account, state practice and doctrine, to answer this fundamental question that, which principles and rules of international law govern cyber espionage.