This book analyses the normative avoidance of cyber-espionage, arguing that it is neither prohibited nor authorised by international law. This situation did not emerge by chance but through the purposeful silence of States, leaving them free to pursue cyber-espionage themselves at the same time as they both try to prevent and fall victim to it.

Part I: IntroductionIntroduction to Part I1 Main notions1.1 The concept of ‘cyber-espionage’1.2 The concept of ‘cyber-space’2 Methodological and conceptual frameworks2.1 The determination of law2.1.1 The approach to treaty interpretation2.1.2 The approach to sources2.2 The concept of normative avoidance2.2.1 Definition2.2.2 NoveltyPart II: The rules connected to territorial integrityIntroduction to Part II3 Territorial sovereignty3.1 The dissimilarities between physical trespass and digital intrusion3.1.1 Espionage per se is not an international wrongful act3.1.2 The lack of an analogy between digital and physical intrusions3.2 The ‘do-not-harm’ challenge and the minimal effects of cyber-espionage4 Collective security law4.1 A traditional interpretation of the UN Charter does not result in a regulation of cyber-espionage4.2 Alternative interpretations of cyber-espionage do not result in the regulation of cyber-espionage4.2.1 Interpretation based on meta-rules4.2.2 Teleological interpretation5 The law applicable between belligerent States5.1 The territorial rationale of the regulation of espionage between belligerents5.1.1 The categories of spies defined by the law of armed conflict5.1.2 The challenging application of rules about espionage in a digital space5.2 A lack of State support in favour of the application of espionage-related rules in cyber-space6 The law applicable between belligerent and non-belligerent States6.1 The absence of a regulation by rules on material operations6.1.1 The obligations between belligerents6.1.2 The obligations on neutral States6.2 A limited restriction of cyber-espionage by rules on the use of telecommunications6.2.1 The obligations between belligerents6.2.2 The obligations on neutral StatesConclusion to Part IIPart III: The rules disconnected from territorial integrityIntroduction to Part III7 The law of diplomatic relations7.1 Indirect regulation of espionage by embassies7.1.1 The accreditation of the mission7.1.2 The performing of the mission7.2 Indirect regulation of espionage on embassies7.2.1 The lack of regulation by the inviolability of diplomatic premises7.2.2 The incompatibility of cyber-espionage with the rules protecting the inviolability of archives and documents8 International economic law8.1 The absence of a prohibition of economic cyber-espionage8.1.1 The absence of a prohibition by national treatment8.1.2 The absence of a prohibition by the obligation to protect undisclosed information8.2 The tolerance of cyber-espionage required for the preservation of essential security interests8.2.1 Cyber-espionage activities in peacetime8.2.2 Cyber-espionage in a time of war or other emergency in international relations9 International human rights law9.1 The absence of extraterritorial jurisdiction in the event of remote cyber-espionage activities9.2 The measured regulation of surveillance activities by the right to privacy9.2.1 Interference and legality9.2.2 Legitimacy and proportionality10 State practice10.1 The unanimous prohibition of espionage by domestic criminal laws10.1.1 The traditional prohibition of espionage10.1.2 The progressive prohibition of digital intrusions and interceptions10.2 The predominant authorisation of one’s own intelligence activities against other States10.2.1 Provisions authorising intelligence gathering10.2.2 Grounds allowing intelligence collection11 Opinio juris11.1 The absence of a right to spy11.2 The absence of a prohibition on espionageConclusion to Part IIIConclusionIndex

While espionage between states is a practice dating back centuries, the emergence of the internet revolutionised the types and scale of intelligence activities, creating drastic new challenges for the traditional legal frameworks governing them.This book argues that cyber-espionage has come to have an uneasy status in law: it is not prohibited, because spying does not result in an internationally wrongful act, but neither is it authorised or permitted, because states are free to resist foreign cyber-espionage activities. Rather than seeking further regulation, however, governments have remained purposefully silent, leaving them free to pursue cyber-espionage themselves at the same time as they adopt measures to prevent falling victim to it.Drawing on detailed analysis of state practice and examples from sovereignty, diplomacy, human rights and economic law, this book offers a comprehensive overview of the current legal status of cyber-espionage, as well as future directions for research and policy. It is an essential resource for scholars and practitioners in international law, as well as anyone interested in the future of cyber-security.