From International cyber law: interactive toolkit
Revision as of 09:15, 13 September 2021 by Ccdcoe630 (talk | contribs)
Jump to navigation Jump to search

As a rule, the conduct of State organs is attributable to the State in question;[1] by contrast, the conduct of non-State actors or third States’ organs can only be attributed to the State under specific circumstances.[2]

State organs and persons and entities in exercise of governmental authority

State organs and persons and entities in exercise of governmental authority
The following types of conduct of State organs and persons and entities in exercise of governmental authority are attributable to a State:
  1. The conduct of any of the organs of that State, "whether the organ exercises legislative, executive, judicial or any other functions, whatever position it holds in the organization of the State, and whatever its character as an organ of the central Government or of a territorial unit of the State";[3]
  2. The conduct of an organ of another State placed at the disposal of the State in question, if "the organ is acting in the exercise of elements of the governmental authority" of the latter State;[4]
  3. The conduct of "a person or entity which is not an organ of the State […] but which is empowered by the law of that State to exercise elements of the governmental authority, […] provided the person or entity is acting in that capacity in the particular instance."[5]

Such conduct is attributable to the State even if the organ, person or entity acting in that capacity "exceeds its authority or contravenes instructions" (acts ultra vires).[6]

Non-State actors

Non-State actors
Activities of non-State actors (groups and individuals) are generally not attributable to States. However, such conduct can be attributable to a State in particular if the actor is:
  1. "in fact acting on the instructions of, or under the direction or control of, that State in carrying out the conduct";[7]
  2. "in fact exercising elements of the governmental authority in the absence or default of the official authorities and in circumstances such as to call for the exercise of those elements of authority";[8]
  3. "an insurrectional movement which becomes the new Government of a State";[9] or
  4. "a movement, insurrectional or other, which succeeds in establishing a new State in part of the territory of a pre-existing State or in a territory under its administration".[10]


  1. the conduct of a non-State actor is attributable to a State "if and to the extent that the State acknowledges and adopts the conduct in question as its own".[11]

Evidentiary standards

Evidentiary standards
Evidentiary standards applicable to the attribution of cyber activities are context-dependent.[12] The law of State responsibility as such does not contain generally applicable burdens, standards, or methods of proof,[13] and these matters are instead ordinarily determined by the relevant forum.[14]

However, in case a State is considering a response to an internationally wrongful act, the standard of attribution is that of "reasonableness", i.e. "States must act as reasonable States would in the same or similar circumstances when considering responses to them."[15] This depends, among other factors, on the "reliability, quantum, directness, nature (e.g., technical data, human intelligence), and specificity of the relevant available information when considered in light of the attendant circumstances and the importance of the right involved."[16] Nevertheless, there is no obligation to publicly provide the evidence.[17]

Specific rules may apply to some responses, so when State A responds with countermeasures after misattributing an internationally wrongful act to State B, it commits an internationally wrongful act of its own, even though it correctly applied the "reasonableness" standard of attribution.[18]

National positions








New Zealand

Norway: 2021

National position of Norway:2021

Romania: 2021

National position of Romania:2021


The Netherlands

United Kingdom

"As with other forms of hostile activity, there are technical, political and diplomatic considerations in publicly attributing hostile cyber activity to a state, in addition to whether the legal test is met.

There is no legal obligation requiring a state to publicly disclose the underlying information on which its decision to attribute hostile activity is based, or to publicly attribute hostile cyber activity that it has suffered in all circumstances.

However, the UK can and does attribute malicious cyber activity where we believe it is in our best interests to do so, and in furtherance of our commitment to clarity and stability in cyberspace. Sometimes we do this publicly, and sometimes we do so only to the country concerned. We consider each case on its merits.

For example, the WannaCry ransomware attack affected 150 countries, including 48 National Health Service Trusts in the United Kingdom. It was one of the most significant attacks to hit the UK in terms of scale and disruption. In December 2017, together with partners from the US, Australia, Canada, New Zealand, Denmark and Japan, we attributed the attack to North Korean actors. Additionally, our attribution, together with eleven other countries, of the destructive NotPetya cyber-attack against Ukraine to the Russian government, specifically the Russian Military in February this year illustrated that we can do this successfully. If more states become involved in the work of attribution then we can be more certain of the assessment. We will continue to work closely with allies to deter, mitigate and attribute malicious cyber activity. It is important that our adversaries know their actions will be held up for scrutiny as an additional incentive to become more responsible members of the international community."[19]

United Kingdom: 2021

"The term ‘attribution’ is used in relation to cyberspace in both a legal and non-legal sense. It is used in a legal sense to refer to identifying those who are responsible for an internationally wrongful act. It is also used in a non-legal sense to describe the identification of actors (including non-state actors) who have carried out cyber conduct which may be regarded as hostile or malicious but does not necessarily involve an internationally wrongful act.

For the UK, there are technical and diplomatic considerations in determining whether to attribute publicly such activities in cyberspace. The decision whether to make a public attribution statement is a matter of policy. Each case is considered on its merits. The UK will publicly attribute conduct in furtherance of its commitment to clarity and stability in cyberspace or where it is otherwise in its interests to do so.

Whatever the nature of the attribution, there is no general legal obligation requiring a State to publicly disclose any underlying information on which its decision to attribute conduct is based."[20]

United States of America: 2012

"[...]cyberspace significantly increases an actor’s ability to engage in attacks with “plausible deniability,” by acting through proxies. I noted that legal tools exist to ensure that states are held accountable for those acts. What I want to highlight here is that many of these challenges — in particular, those concerning attribution — are as much questions of a technical and policy nature rather than exclusively or even predominantly questions of law. Cyberspace remains a new and dynamic operating environment, and we cannot expect that all answers to the new and confounding questions we face will be legal ones."[21]

United States of America: 2016

"From a legal perspective, the customary international law of state responsibility supplies the standards for attributing acts, including cyber acts, to States. For example, cyber operations conducted by organs of a State or by persons or entities empowered by domestic law to exercise governmental authority are attributable to that State, if such organs, persons, or entities are acting in that capacity.

Additionally, cyber operations conducted by non-State actors are attributable to a State under the law of state responsibility when such actors engage in operations pursuant to the State’s instructions or under the State’s direction or control, or when the State later acknowledges and adopts the operations as its own.

Thus, as a legal matter, States cannot escape responsibility for internationally wrongful cyber acts by perpetrating them through proxies. When there is information — whether obtained through technical means or all-source intelligence — that permits a cyber act engaged in by a non-State actor to be attributed legally to a State under one of the standards set forth in the law of state responsibility, the victim State has all of the rights and remedies against the responsible State allowed under international law.

The law of state responsibility does not set forth explicit burdens or standards of proof for making a determination about legal attribution. In this context, a State acts as its own judge of the facts and may make a unilateral determination with respect to attribution of a cyber operation to another State. Absolute certainty is not—and cannot be—required. Instead, international law generally requires that States act reasonably under the circumstances when they gather information and draw conclusions based on that information.

I also want to note that, despite the suggestion by some States to the contrary, there is no international legal obligation to reveal evidence on which attribution is based prior to taking appropriate action. There may, of course, be political pressure to do so, and States may choose to reveal such evidence to convince other States to join them in condemnation, for example. But that is a policy choice—it is not compelled by international law."[22]


See also

Notes and references

  1. ILC Articles on State Responsibility, Art 4.
  2. ILC Articles on State Responsibility, Art 8.
  3. ILC Articles on State Responsibility, Art 4(1).
  4. ILC Articles on State Responsibility, Art 6.
  5. ILC Articles on State Responsibility, Art 5.
  6. ILC Articles on State Responsibility, Art 7; Tallinn Manual 2.0, commentary to rule 15, paras. 6-7 and 12.
  7. ILC Articles on State Responsibility, Art 8; see also Kubo Mačák, ‘Decoding Article 8 of the International Law Commission’s Articles on State Responsibility: Attribution of Cyber Operations by Non-State Actors’ (2016) 21 JC&SL 405.
  8. ILC Articles on State Responsibility, Art 9.
  9. ILC Articles on State Responsibility, Art 10(1).
  10. ILC Articles on State Responsibility, Art 10(2).
  11. ILC Articles on State Responsibility, Art 11.
  12. See further Marco Roscini, ‘Evidentiary Issues in International Disputes Related to State Responsibility for Cyber Operations’ (2015) 50 Texas International Law Journal 233; Isabella Brunner, Marija Dobrić and Verena Pirker, ‘Proving a State’s Involvement in a Cyber-Attack: Evidentiary Standards Before the ICJ’ (2015) 25 Finnish Yearbook of International Law 75; Tomohiro Mikanagi and Kubo Mačák, ‘Attribution of Cyber Operations: An International Law Perspective on the Park Jin Hyok case’ (2020) 9 Cambridge International Law Journal 51, 64-68.
  13. ILC Articles on State Responsibility, commentary to chapter III, para 4 ("Questions of evidence and proof of such a breach fall entirely outside the scope of the articles."); ibid, commentary to Art 19, para 8 ("Just as the articles do not deal with questions of the jurisdiction of courts or tribunals, so they do not deal with issues of evidence or the burden of proof.").
  14. Tallinn Manual 2.0, Chapter 4 Section 1, para 8.
  15. Tallinn Manual 2.0, Chapter 4 Section 1, para 10; Cf. Yeager v Islamic Republic of Iran (1987) 17 Iran-US CTR 92, 101–02 (‘[I]n order to attribute an act to the State, it is necessary to identify with reasonable certainty the actors and their association with the State.’).
  16. Tallinn Manual 2.0, Chapter 4 Section 1, para 10.
  17. According to the UK Attorney General, "[t]here is no legal obligation requiring a state to publicly disclose the underlying information on which its decision to attribute hostile activity is based, or to publicly attribute hostile cyber activity that it has suffered in all circumstances." (UK Attorney General, Jeremy Wright QC MP, 'Cyber and International Law in the 21st Century'; see also Tallinn Manual 2.0, Chapter 4 Section 1 chapeau, para 13.
  18. Tallinn Manual 2.0, Chapter 4 Section 1, para 12; see also ILC Articles on State Responsibility, Art 49 para 3 (“A State taking countermeasures acts at its peril, if its view of the question of wrongfulness turns out not to be well founded.”)
  19. Attorney General Jeremy Wright:Cyber and International Law in the 21st Century, 23 May 2018
  20. United Kingdom Foreign, Commonwealth & Development Office, Application of international law to states’ conduct in cyberspace: UK statement, 3 June 2021
  21. Harold Hongju Koh, International Law in Cyberspace, 18 September 2012, 8
  22. Brian J. Egan, International Law and Stability in Cyberspace, 10 November 2016 17-20.

Bibliography and further reading