Definition[edit | edit source]
|Sovereignty is a core principle of international law. According to a widely accepted definition of the term in the 1928 Island of Palmas arbitral award,|
Multiple declarations by the UN, NATO, OSCE, the European Union, and individual States have confirmed that international law applies in cyberspace. Accordingly, so too does the principle of sovereignty. However, there is some debate as to whether this principle operates as a standalone rule of international law, the breach of which gives rise to state responsibility.
The remainder of this section proceeds on the basis of the former “sovereignty-as-rule” approach. Those espousing the latter “sovereignty-as-principle” approach should refer to other relevant sections of the legal analysis (such as that on the prohibition of intervention).
It is understood that sovereignty has both an internal and an external component. In the cyber context, the “internal” facet of sovereignty entails that “[a] State enjoys sovereign authority with regard to the cyber infrastructure, persons, and cyber activities located within its territory, subject to its international legal obligations.”
As a general rule, each State must respect the sovereignty of other States. It is clear that a cyber operation with severe destructive effects, comparable to a “non-cyber” armed attack or a use of force against a State, constitutes a violation of its sovereignty; however, with more subtle cyber operations, the question is far from settled.
The following modalities, highlighted in the Tallinn Manual 2.0, represent different ways of determining what a “sovereignty violation” might mean in the context of cyber operations:
The Tallinn Manual’s view of what constitutes a violation of sovereignty has been expressly endorsed by several States including Germany and the Netherlands. An alternative test has been proposed by France, which argues that a breach of sovereignty occurs already when there is “any unauthorised penetration by a State of [the victim State’s] systems”.
Attributing the relevant cyber operation to a State different from the target State is a necessary prerequisite for qualifying the cyber operation as a violation of the target State's sovereignty.
Whether non-State actors can violate territorial sovereignty on their own is a matter of disagreement.
National positions[edit | edit source]
"To the extent that a State enjoys the right to exercise sovereignty over objects and activities within its territory, it necessarily shoulders corresponding responsibilities to ensure those objects and activities are not used to harm other States."
"[...]the Czech Republic recalls that the principles of sovereignty and sovereign equality of States are cornerstones of the UN Charter and thus concurs with the conclusion contained in the report of the UN GGE that in their use of ICT´s States are obliged to observe principles of international law, including the principle of sovereignty. The Czech Republic concurs with those considering the principle of sovereignty as an independent right and the respect to sovereignty as an independent obligation.
The Czech Republic firmly believes that under this principle States may freely exercise without interference in any form by another State both aspects of sovereignty in cyberspace, be it an internal one, with the exclusive jurisdiction over the ICTs located on its territory, or the external one, including the determination of its foreign policy, subject only to obligations under international law. The Czech Republic considers the following cyber operations in a State’s territory as violation of its sovereignty, if attributable to another State:
A. a cyber operation causing death or injury to persons or significant physical damage;
B.a cyber operation causing damage to or disruption of cyber or other infrastructure with a significant impact on national security, economy, public health or environment;
C.a cyber operation interfering with any data or services which are essential for the exercise of inherently governmental functions, and thereby significantly disrupting the exercise of those functions; for example, distributing ransomware which encrypts the computers used by a government and thus significantly delaying the payment of retirement pensions ;
D. cyber operation against a State or entities or persons located therein, including international organisations, conducted by a physically present organ of another State;"
"Sovereignty entails not only rights, but also obligations."
"It is undisputed that the principle of State sovereignty applies in cyberspace. While cyberspace as a whole cannot be subject to appropriation by any State, each State has jurisdiction over the cyber infrastructure and the persons engaged in cyber activities within its territory."
"Finland sees sovereignty as a primary rule of international law, a breach of which amounts to an internationally wrongful act and triggers State responsibility. This rule is fully applicable in cyberspace. Whether an unauthorized cyber intrusion violates the target State’s sovereignty depends on its nature and consequences and is subject to a case-by-case assessment."
"Cyberattacks may constitute a violation of sovereignty. The international norms and principles that flow from State sovereignty apply to the use of ICT by States and to their territorial jurisdiction over ICT infrastructure. France exercises its sovereignty over the information systems located on its territory".
"Any cyberattack against French digital systems or any effects produced on French territory by digital means by a State organ, a person or an entity exercising elements of governmental authority or by a person or persons acting on the instructions of or under the direction or control of a State constitutes a breach of sovereignty."
"The principle of sovereignty applies to cyberspace. France exercises its sovereignty over the information systems located on its territory. The gravity of a breach of sovereignty will be assessed on a case-by-case basis in accordance with French cyberdefence governance arrangements in order to determine possible responses in compliance with international law".
"The legal principle of State sovereignty applies to States’ activities with regard to cyberspace. State sovereignty implies, inter alia, that a State retains a right of regulation, enforcement and adjudication (jurisdiction) with regard to both persons engaging in cyber activities and cyber infrastructure on its territory. It is limited only by relevant rules of international law, including international humanitarian law and international human rights law. Germany recognizes that due to the high degree of cross-border interconnectedness of cyber infrastructures, a State’s exercise of its jurisdiction may have unavoidable and immediate repercussions for the cyber infrastructure of other States. While this does not limit a State’s right to exercise its jurisdiction, due regard has to be given to potential adverse effects on third States.
By virtue of sovereignty, a State’s political independence is protected and it retains the right to freely choose its political, social, economic and cultural system. Inter alia, a State may generally decide freely which role information and communication technologies should play in its governmental, administrative and adjudicative proceedings. Foreign interference in the conduct of elections of a State may under certain circumstances constitute a breach of sovereignty or, if pursued by means of coercion, of the prohibition of wrongful intervention. Moreover, by virtue of its sovereignty, a State may decide freely over its foreign policy also in the field of information and communication technologies.
Furthermore, a State’s territorial sovereignty is protected. Due to the rootedness of all cyber activities in the actions of human beings using physical infrastructure, cyberspace is not a deterritorialized forum. In this regard, Germany underlines that there are no independent ‘cyber borders’ incongruent with a State’s physical borders which would limit or disregard the territorial scope of its sovereignty. Within its borders, a State has the exclusive right – within the framework of international law – to fully exercise its authority, which includes the protection of cyber activities, persons engaging therein as well as cyber infrastructures in the territory of a State against cyber and non-cyber-related interferences attributable to foreign States."
"Germany agrees with the view that cyber operations attributable to States which violate the sovereignty of another State are contrary to international law. In this regard, State sovereignty constitutes a legal norm in its own right and may apply directly as a general norm also in cases in which more specific rules applicable to State behaviour, such as the prohibition of intervention or the use of force, are not applicable. Violations of State sovereignty may inter alia involve its territorial dimension; in this regard, the following categories of cases may be relevant (without excluding the possibility of other cases):
Germany essentially concurs with the view proffered, inter alia, in the Tallinn Manual 2.0 that cyber operations attributable to a State which lead to physical effects and harm in the territory of another State constitute a violation of that State’s territorial sovereignty. This encompasses physical damage to cyber infrastructure components per se and physical effects of such damage on persons or on other infrastructure, i.e. cyber or analogue infrastructure components connected to the damaged cyber component or infrastructure located in the vicinity of the damaged cyber infrastructure (provided a sufficient causal link can be established).
Germany generally also concurs with the view expressed and discussed in the Tallinn Manual 2.0 that certain effects in form of functional impairments with regard to cyber infrastructures located in a State’s territory may constitute a violation of a State’s territorial sovereignty. In Germany’s view, this may also apply to certain substantial non-physical (i.e. software-related) functional impairments. In such situations, an evaluation of all relevant circumstances of the individual case will be necessary. If functional impairments result in substantive secondary or indirect physical effects in the territory of the target State (and a sufficient causal link to the cyber operation can be established), a violation of territorial sovereignty will appear highly probable.
In any case, negligible physical effects and functional impairments below a certain impact threshold cannot – taken by themselves – be deemed to constitute a violation of territorial sovereignty.
Generally, the fact that a piece of critical infrastructure (i.e. infrastructure which plays an indispensable role in ensuring the functioning of the State and its society) or a company of special public interest in the territory of a State has been affected may indicate that a State’s territorial sovereignty has been violated. However, this cannot in and of itself constitute a violation, inter alia because uniform international definitions of the terms do not yet exist. Also, cyber operations in which infrastructures and/or companies which do not qualify as ‘critical’ or ‘of particular public interest’ are affected may likewise violate the territorial sovereignty of a State."
Iran[edit | edit source]
"Article II: Sovereignty Policies of Armed forces of the Islamic Republic of Iran
1. The Islamic Republic of Iran has developed its sovereignty fields consistent with necessary capabilities for protection of its strategic military, economic, social, cultural, and political authority. In doing so, the development of expertise and advanced cyber tools for active and deterrent cyber-defense is, among others, one of the significant priorities for the protection of the strategic authority of the state.
2. Rules of modern international law imply the existence of limited territory in geographical borders of states exercising sovereignty or at least jurisdiction within those borders. According to the armed forces of the Islamic Republic of Iran, the territorial sovereignty and jurisdiction of the states are also extended to all elements of the cyberspace.
3. Any intentional use of cyber-force with tangible or non-tangible implications which is or can be a threat to the national security or may, due to political, economic, social, and cultural destabilization, result in destabilization of national security constitutes a violation of the sovereignty of the state.
4. Any utilization of cyberspace if and when involves unlawful intrusion to the (public or private) cyber structures which is under the control of another state, maybe constituted as the violation of the sovereignty of the targeted state.
5. The sovereignty of states is not an extra-legal matter. It shall be interpreted under the other fundamental legal principles such as non-intervention, good faith, self-determination, and other basic principles. It must be kept in mind that the sovereignty of states is subject to the principle of equality and the sovereignty of any state is not above the sovereignty of the other states. Therefore, any limiting and freezing measure, including sanctions, constitutes the violation of the sovereignty of independent states because of not respecting the sovereignty of target states."
"To begin with, there are diverging views regarding whether sovereignty is merely a principle, from which legal rules are derived, or a binding rule of international law in itself, the violation of which could be considered an internationally wrongful act. This issue has many facets, and while I will not offer any definitive position for the time being, I would like to stress a number of important points.
A second, and related, point is that States undoubtedly have sovereign interests in protecting cyber infrastructure and data located in their territory. However, States may also have legitimate sovereign interests with respect to data outside their territory. For example, as governments store more and more of their data by using cloud services provided by third parties, whose servers are located abroad, how do we describe the interest that they have in relation to that data? Would the interest in protecting the data not be a sovereign interest in this case as well? Or, alternatively, when a State conducts a criminal investigation and needs to access data located abroad from its own territory, under what circumstances does it need to request the consent of the territorial State? Of course, there are no easy answers to these questions, and some of them are currently being discussed, such as in the context of the protocol to the Budapest Cybercrime Convention currently being negotiated to address this very topic.
These questions reflect an inherent tension between States’ legitimate interest and the concept of territorial sovereignty, as we understand it in the physical world. In practice, States occasionally do conduct cyber activities that transit through, and target, networks and computers located in other States, for example for national defense, cybersecurity, or law enforcement purposes. Under existing international law, it is not clear whether these types of actions are violations of the rule of territorial sovereignty, or perhaps that our understanding of territorial sovereignty in cyberspace is substantively different from its meaning in the physical world."
Japan[edit | edit source]
"A State must not violate the sovereignty of another State by cyber operations. Moreover, a State must not intervene in matters within domestic jurisdiction of another State by cyber operations."
"On the other hand, regarding a violation of sovereignty that does not necessarily constitute an intervention, in the Lotus case, the Permanent Court of International Justice held that a State may not exercise its power in the territory of another State, while, in the Island of Palmas case, the Arbitral Tribunal stated as follows: "Sovereignty in the relations between States signifies independence. Independence in regard to a portion of the globe is the right to exercise therein, to the exclusion of any other State, the functions of a State." Taking these and other judgments into account, the Government of Japan considers that there exist certain forms of violation of sovereignty which may not necessarily constitute unlawful intervention prohibited under the principle of non-intervention.
With respect to violation of sovereignty, the International Court of Justice (ICJ), in the Nicaragua case (1986), held that the United States had acted in breach of its obligation under customary international law not to intervene in the affairs of another State, and, in addition, that the United States, by directing or authorizing overflights of Nicaraguan territory, had acted in breach of its obligation under customary international law not to violate the sovereignty of another State. In addition, in the Costa Rica v. Nicaragua case (2015), the ICJ cited the absence of evidence that Costa Rica exercised authority on Nicaragua ’s territory as the reason for dismissing Nicaragua's claim concerning the violation of its territorial integrity and sovereignty. Considering these cases, it can be presumed that, in some cases, a violation of sovereignty constitutes a violation of international law even when it does not fall within the scope of unlawful intervention."
"An act of causing physical damage or loss of functionality by means of cyber operations against critical infrastructure, including medical institutions, may constitute an unlawful intervention, depending on the circumstances, and at any rate, it may constitute a violation of sovereignty. As various opinions were expressed on the relationship between violation of sovereignty and unlawful intervention at the sixth GGE and the OEWG, it is desirable that a common understanding be forged through State practices and future discussions."
"The principle of sovereignty prohibits the interference by one state in the inherently governmental functions of another and prohibits the exercise of state power or authority on the territory of another state. In the physical realm, the principle has legal effect through the prohibition on the use of force, through the rule of non-intervention and also through a standalone rule of territorial sovereignty. Subject to limited exceptions (e.g. authorisation by the United Nations Security Council, self-defence, consent), that standalone rule prohibits a state from sending its troops or police forces into or through, or its aircraft over, foreign territory, and prohibits a state from carrying out official investigations or otherwise exercising jurisdiction on foreign territory.
In the cyber realm, the principle of sovereignty is given effect through the prohibition on the use of force and the rule of non-intervention. New Zealand considers that the standalone rule of territorial sovereignty also applies in the cyber context but acknowledges that further state practice is required for the precise boundaries of its application to crystallise.
In New Zealand’s view, the application of the rule of territorial sovereignty in cyberspace must take into account some critical features that distinguish cyberspace from the physical realm. In particular: i) cyberspace contains a virtual element which has no clear territorial link; ii) cyber activity may involve cyber infrastructure operating simultaneously in multiple territories and diffuse jurisdictions; and iii) the lack of physical distance in cyberspace means malicious actors can apply instantaneous effects on targets without warning. These features present unique opportunities for malicious actors and significant defensive challenges for states. They also make it difficult for states to prevent malicious cyber activity being conducted from or routed through their territory.
Bearing those factors in mind, and having regard to developing state practice, New Zealand considers that territorial sovereignty prohibits states from using cyber means to cause significant harmful effects manifesting on the territory of another state. However, New Zealand does not consider that territorial sovereignty prohibits every unauthorised intrusion into a foreign ICT system or prohibits all cyber activity which has effects on the territory of another state. There is a range of circumstances – in addition to pure espionage activity – in which an unauthorised cyber intrusion, including one causing effects on the territory of another state, would not be internationally wrongful. For example, New Zealand considers that the rule of territorial sovereignty as applied in the cyber context does not prohibit states from taking necessary measures, with minimally destructive effects, to defend against the harmful activity of malicious cyber actors.
A detailed factual enquiry is required in each case to determine whether state cyber activity that has effects manifesting on the territory of another state, but which does not amount to a use of force or a prohibited intervention, nonetheless involves a violation of the standalone rule of territorial sovereignty. That factual enquiry should take into account the scale and significance of the effects, the objective of the activity, and the nature of the target."
"State sovereignty is also applicable to cyberspace.8 Owing to the special characteristics of cyberspace, which has no clear territorial boundaries, putting the principle of sovereignty into practice is a particular challenge. One major issue is who has jurisdiction over or access to digital data. In the cyber context, the key question is which states have legitimate control over digital data and are authorised to access that data – which may, depending on the circumstances, be stored on a different territory or may not be localised geographically. Conversely, in terms of interstate relations at cybersecurity level, the principle of sovereignty provides wide scope for protection against cyber operations.For example, state sovereignty protects information and communication technologies (ICT) infrastructure on a state's territory against unauthorised intrusion or material damage. This includes the computer networks, systems and software supported by the ICT infrastructure, regardless of whether the infrastructure is private or public.
Switzerland recognises that defining what constitutes a violation of the principle of sovereignty in cyberspace is particularly challenging and has yet to be clarified conclusively. It supports considering the following two criteria in such assessments: first, does the incident violate the state's territorial integrity and second, does it constitute interference with or usurpation of an inherently governmental function. A precise definition of these criteria is a question of interpretation and subject to debate. The current debate includes among other aspects i) incidents whereby the functionality of infrastructure or related equipment has been damaged or limited, ii) cases where data has been altered or deleted, interfering with the fulfilment of inherently governmental functions such as providing social services, conducting elections and referendums, or collecting taxes, and iii) situations in which a state has sought to influence, disrupt or delay democratic decision-making processes in another state through the coordinated use of legal and illegal methods in cyberspace e.g. propaganda, disinformation and covert actions by intelligence services. The assessment of an individual case depends on the nature of the cyber incident and its repercussions."
"[..]a further contested area amongst those engaged in the application of international law to cyber space is the regulation of activities that fall below the threshold of a prohibited intervention, but nonetheless may be perceived as affecting the territorial sovereignty of another state without that state’s prior consent. Some have sought to argue for the existence of a cyber specific rule of a “violation of territorial sovereignty” in relation to interference in the computer networks of another state without its consent. Sovereignty is of course fundamental to the international rules-based system. But I am not persuaded that we can currently extrapolate from that general principle a specific rule or additional prohibition for cyber activity beyond that of a prohibited intervention. The UK Government’s position is therefore that there is no such rule as a matter of current international law.
"Sovereignty, as a general principle, is a fundamental concept in international law. The United Kingdom recalls that any prohibition on the activities of States whether in relation to cyberspace or other matters, must be clearly established either in customary international law or in a treaty binding upon the States concerned. The United Kingdom does not consider that the general concept of sovereignty by itself provides a sufficient or clear basis for extrapolating a specific rule or additional prohibition for cyber conduct going beyond that of non-intervention referred to above. At the same time, the United Kingdom notes that differing viewpoints on such issues should not prevent States from assessing whether particular situations amount to internationally wrongful acts and arriving at common conclusions on such matters."
"States conducting activities in cyberspace must take into account the sovereignty of other states, including outside the context of armed conflict. The physical infrastructure that supports the Internet and cyber activities is generally located in sovereign territory and subject to the jurisdiction of the territorial state. Because of the interconnected, interoperable nature of cyberspace, operations targeting networked information infrastructures in one country may create effects in another country. Whenever a state contemplates conducting activities in cyberspace, the sovereignty of other states needs to be considered."
"[..] remote cyber operations involving computers or other networked devices located on another State’s territory do not constitute a per se violation of international law. In other words, there is no absolute prohibition on such operations as a matter of international law. This is perhaps most clear where such activities in another State’s territory have no effects or de minimis effects.
Most States, including the United States, engage in intelligence collection abroad. As President Obama said, the collection of intelligence overseas is “not unique to America.” As the President has also affirmed, the United States, like other nations, has gathered intelligence throughout its history to ensure that national security and foreign policy decisionmakers have access to timely, accurate, and insightful information. Indeed, the President issued a directive in 2014 to clarify the principles that would be followed by the United States in undertaking the collection of signals intelligence abroad.
Such widespread and perhaps nearly universal practice by States of intelligence collection abroad indicates that there is no per se prohibition on such activities under customary international law. I would caution, however, that because “intelligence collection” is not a defined term, the absence of a per se prohibition on these activities does not settle the question of whether a specific intelligence collection activity might nonetheless violate a provision of international law.
Although certain activities—including cyber operations — may violate another State’s domestic law, that is a separate question from whether such activities violate international law. The United States is deeply respectful of other States’ sovereign authority to prescribe laws governing activities in their territory. Disrespecting another State’s domestic laws can have serious legal and foreign policy consequences. As a legal matter, such an action could result in the criminal prosecution and punishment of a State’s agents in the United States or abroad, for example, for offenses such as espionage or for violations of foreign analogs to provisions such as the U.S. Computer Fraud and Abuse Act. From a foreign policy perspective, one can look to the consequences that flow from disclosures related to such programs. But such domestic law and foreign policy issues do not resolve the independent question of whether the activity violates international law."
Appendices[edit | edit source]
See also[edit | edit source]
- Scenario 01: Election interference
- Scenario 02: Cyber espionage against government departments
- Scenario 03: Cyber operation against the power grid
- Scenario 05: State investigates and responds to cyber operations against private actors in its territory
- Scenario 07: Leak of State-developed hacking tools
- Scenario 08: Certificate authority hack
- Scenario 09: Economic cyber espionage
- Scenario 11: Sale of surveillance tools in defiance of international sanctions
- Scenario 14: Ransomware campaign
- Scenario 17: Collective responses to cyber operations
Notes and references[edit | edit source]
- Island of Palmas (Neth. v. U.S.), 2 RIAA 829, 838 (Perm. Ct. Arb. 1928).
- UNGA Res 71/237 (30 December 2015) UN Doc A/RES/20/237.
- North Atlantic Treaty Organization, 'Wales Summit Declaration' (issued by the Head of State and Government participating in the meeting of the North Atlantic Council in Wales (5 September 2015) para 72.
- Organization for Security and Cooperation in Europe, Decision No. 1202, OSCE Confidence-Building Measures to Reduce the Risks of Conflict Stemming from the Use of Information and Communication Technologies (Permanent Council, 10 March 2016) PC.DEC/1202.
- Council of the European Union,"Council Conclusions on the Joint Communication to the European Parliament and the Council: Resilience, Deterrence and Defence: Building strong cybersecurity for the EU" (Council conclusions, 20 November 2017).
- Michael N Schmitt, 'Virtual Disenfranchisement: Cyber Election Meddling in the Grey Zones of International Law' (2018) 19 ChiJIntlL 30,40; Tallinn Manual 2.0, commentary to rule 4, para 2 (‘States shoulder an obligation to respect the sovereignty of other States as a matter of international law’).
- Austria, Pre-Draft Report of the OEWG - ICT: Comments by Austria (31 March 2020), stating that ‘a violation of the principle of State sovereignty constitutes an internationally wrongful act – if attributable to a State – for which a target State may seek reparation under the law of State responsibility’.
- Czech Republic, Statement by Mr. Richard Kadlčák, Special Envoy for Cyberspace, 2nd substantive session of the Open-ended Working Group on developments in the field of information and telecommunications in the context of international security (11 February 2020), stating that ‘[t]he Czech Republic concurs with those considering the principle of sovereignty as an independent right and the respect to sovereignty as an independent obligation.’
- Finland, ‘International law and cyberspace: Finland’s national positions’ (15 October 2020), 3, stating that ‘Finland sees sovereignty as a primary rule of international law, a breach of which amounts to an internationally wrongful act and triggers State responsibility. This rule is fully applicable in cyberspace.’
- French Ministry of the Armies, ‘International Law Applied to Operations in Cyberspace’, 9 September 2019, stating that ‘Any unauthorised penetration by a State of French systems or any production of effects on French territory via a digital vector may constitute, at the least, a breach of sovereignty’.
- Germany, ‘On the Application of International Law in Cyberspace: Position Paper’ (March 2021), p. 3, noting that ‘Germany agrees with the view that cyber operations attributable to States which violate the sovereignty of another State are contrary to international law’.
- Iran, ‘Declaration of General Staff of the Armed Forces of the Islamic Republic of Iran Regarding International Law Applicable to the Cyberspace’ (July 2020), para 4 (‘Any utilization of cyberspace if and when involves unlawful intrusion to the (public or private) cyber structures which is under the control of another state, maybe constituted as the violation of the sovereignty of the targeted state.’).
- Dutch Ministry of Foreign Affairs, ‘Letter to the parliament on the international legal order in cyberspace’ (5 July 2019), stating that ‘countries may not conduct cyber operations that violate the sovereignty of another country’.
- Gary P. Corn and Robert Taylor, ‘Sovereignty in the Age of Cyber’ (2017) 111 AJIL Unbound 207, 208 (arguing that sovereignty is ‘a principle of international law that guides state interactions’).
- Jeremy Wright, ‘Cyber and International Law in the 21st Century’ (23 May 2018) (stating that he was ‘not persuaded that we can currently extrapolate from that general principle a specific rule or additional prohibition for cyber activity beyond that of a prohibited intervention. The UK Government’s position is therefore that there is no such rule as a matter of current international law’); see also Memorandum from JM O’Connor, General Counsel of the Department of Defense, ‘International Law Framework for Employing Cyber Capabilities in Military Operations’ (19 January 2017) (considering that sovereignty is not ‘a binding legal norm, proscribing cyber actions by one State that result in effects occurring on the infrastructure located in another State, or that are manifest in another State’), as cited by Sean Watts & Theodore Richard, 'Baseline Territorial Sovereignty and Cyberspace' (2018) 22 Lewis & Clark L. Rev. 771, 829.
- Paul C. Ney, DOD General Counsel Remarks at U.S. Cyber Command Legal Conference, 2 March 2020, arguing that ‘the Department believes there is not sufficiently widespread and consistent State practice resulting from a sense of legal obligation to conclude that customary international law generally prohibits such non-consensual cyber operations in another State’s territory’.
- Cf. James Crawford, Brownlie's Principles of Public International Law (OUP 2012) 448.
- Tallinn Manual 2.0, rule 2.
- Sovereignty over cyber infrastructure derives from the traditional concept of sovereignty, independent of the use of cyberspace. See Wolff Heintschel von Heinegg, 'Territorial Sovereignty and Neutrality in Cyberspace' (2013) 89 Int’l L. Stud. 123 (noting that '[t]erritorial sovereignty [..] implies that, subject to applicable customary or conventional rules of international law, the State alone is entitled to exercise jurisdiction, especially by subjecting objects and persons within its territory to domestic legislation and to enforce these rules.')
- UN GA Res 2625 (XXV) (24 October 1970) (Friendly Relations Declaration), preamble (emphasizing “that the purposes of the United Nations can be implemented only if States enjoy sovereign equality and comply fully with the requirements of this principle in their international relations”); Tallinn Manual 2.0, rule 4.
- Tallinn Manual 2.0, commentary to rule 4, para 5 and 12.
- See, eg, Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v Nicaragua) and Construction of a Road in Costa Rica along the San Juan River (Nicaragua v Costa Rica) (Judgment)  ICJ Rep 665, 704–05, paras 97–99 (holding that the presence of Nicaragua’s military personnel in the territory under Costa Rica’s sovereignty amounted to a violation of Costa Rica’s territorial sovereignty); see also Tallinn Manual 2.0, commentary to rule 4, para 6.
- Tallinn Manual 2.0, commentary to rule 4, para 7; commentary to rule 32, para 9.
- Tallinn Manual 2.0, commentary to rule 4, para 11.
- Tallinn Manual 2.0, commentary to rule 4, para 12.
- Tallinn Manual 2.0, commentary to rule 4, para 13.
- Tallinn Manual 2.0, commentary to rule 4, para 14.
- Tallinn Manual 2.0, commentary to rule 4, para 15.
- Tallinn Manual 2.0, commentary to rule 4, para 16.
- Tallinn Manual 2.0, commentary to rule 4, para 18.
- Germany, ‘On the Application of International Law in Cyberspace: Position Paper’ (March 2021), p. 4.
- Dutch Ministry of Foreign Affairs, ‘Letter to the parliament on the international legal order in cyberspace’ (5 July 2019), p. 3.
- French Ministry of the Armies, International Law Applied to Operations in Cyberspace, p. 6.
- In favour: see, eg, Theodore Christakis, ‘The ICJ Advisory Opinion on Kosovo: Has International Law Something to Say about Secession?’ (2011) 24 LJIL 73, 84; Marcelo Kohen, ‘The Court’s Contribution to Determining the Content of Fundamental Principles of International Law’ in Giorgio Gaja and Jenny Grote Stoutenburg (eds), Enhancing the Rule of Law through the International Court of Justice (Brill 2012) 145. Against: see, eg, Tallinn Manual 2.0, commentary to rule 4, para 3.
- Australian Government, Australia's position on how international law applies to State conduct in cyberspace
- Richard Kadlčák, Statement of the Special Envoy for Cyberspace and Director of Cybersecurity Department of the Czech Republic, 11 February 2021, 3
- President of Estonia: international law applies also in cyber space, 29 May 2019
- International law and cyberspace - Finland's national position
- Ministry of Defense of France, International Law Applied to Operations in Cyberspace, 9 September 2019, 6.
- Ministry of Defense of France, International Law Applied to Operations in Cyberspace, 9 September 2019, 7.
- Ministry of Defense of France, International Law Applied to Operations in Cyberspace, 9 September 2019, 7.
- Federal Government of Germany, On the Application of International Law in Cyberspace, March 2021, 2-3
- Federal Government of Germany, On the Application of International Law in Cyberspace, March 2021, 3-4
- Declaration of General Staff of the Armed Forces of the Islamic Republic of Iran Regarding International Law Applicable to the Cyberspace, August 2020
- Roy Schöndorf, Israel’s Perspective on Key Legal and Practical Issues Concerning the Application of International Law to Cyber Operations, 8 December 2020.
- "Ministry of Foreign Affairs of Japan, Basic Position of the Government of Japan on International Law Applicable to Cyber Operations, 16 June 2021, 2
- Ministry of Foreign Affairs of Japan, Basic Position of the Government of Japan on International Law Applicable to Cyber Operations, 16 June 2021, 2-3
- Ministry of Foreign Affairs of Japan, Basic Position of the Government of Japan on International Law Applicable to Cyber Operations, 16 June 2021, 3
- The Application of International Law to State Activity in Cyberspace, 1 December 2020, 2-3.
- Federal Department of Foreign Affairs, Switzerland's position paper on the application of international law in cyberspace, May 2021, 2-3
- Attorney General Jeremy Wright:Cyber and International Law in the 21st Century, 23 May 2018
- United Kingdom Foreign, Commonwealth & Development Office, Application of international law to states’ conduct in cyberspace: UK statement, 3 June 2021
- Harold Hongju Koh, International Law in Cyberspace, 18 September 2012, 6
- Brian J. Egan, International Law and Stability in Cyberspace, 10 November 2016 11-13.