Mistake of fact (Law of State responsibility)

== Definition ==
Mistake of fact (Law of State responsibility)
Mistake of fact plays a role in some areas of international law, such as international criminal law or the law of international treaties.Marko Milanovic, ‘Mistakes of Fact When Using Lethal Force in International Law: Part I’ (EJIL:Talk!), and the following parts. With respect to the law of State responsibility, relevance of mistake of fact can be discussed in the context of the criteria establishing State responsibility and of the circumstances precluding wrongfulness.
With respect to the criteria for the establishment of international responsibility (breach of an international obligation and attribution), possible mistakes of fact do not play any role since these criteria are objective in nature,There are some subjective elements in the realm of derivative responsibility discussed below (eg. aid or assistance or coercion). See James Crawford, State Responsibility: The General Part (CUP 2013) 405. which means that subjective considerations are not directly relevant.James Crawford, State Responsibility: The General Part (CUP 2013) 61; ILC Articles on State Responsibility, Commentary to Art. 2, para 3; Mary Ellen O'Connell. The Power & Purpose of International Law: Insights from the Theory & Practice of Enforcement (OUP 2008) 248. For an explanation of a different approach, see Giuseppe Palmisano, ‘Fault’, in Rüdiger Wolfrum (ed) Max Planck Encyclopedia of Public International Law (updated September 2007) para 6-14.
The same applies to the question of the relevance of mistakes of fact with respect to circumstances precluding wrongfulness. First, a mistake of fact does not constitute a standalone circumstance precluding wrongfulness recognized in international law, including in cyberspace. This is evidenced by the fact that errors or mistakes of fact are absent from the authoritative list of such circumstances in the ILC’s Articles on State Responsibility.François Delerue, Cyber Operations and International Law (CUP 2020), 228; Mary Ellen O'Connell. The Power & Purpose of International Law: Insights from the Theory & Practice of Enforcement (OUP 2008) 249; See also the argumentation in favour of “objectivist” approach in Marko Milanovic, ‘Mistakes of Fact When Using Lethal Force in International Law: Part II’ (EJIL:Talk!). There are few opinions that mistake of fact might qualify as a circumstance precluding wrongfulness, but often they are not further elaborated on. See for example Second report on State responsibility, by Mr. James Crawford, Special Rapporteur (1994, A/CN.4/498 and Add.1–4) para 262. An error has significant legal relevance in some other sub-fields of international law, for example as a ground for invalidity of international treaties - see Article 48 of the Vienna Convention on the Law of Treaties from 1969, or in context of international criminal law – see for example Art. 32 para 1 of the Rome Statute of the International Criminal Court from 1998. See an overview of state practice on the relevance of mistake of facts in various sub-fields of international law in Marko Milanovic, ‘Mistakes of Fact When Using Lethal Force in International Law: Part I’ (EJIL:Talk!), and the following parts. 
Second, a mistake of fact also cannot serve as a ground for the invocation of any of the established circumstances precluding wrongfulness since none of them requires an inquiry into a subjective element, such as faultMary Ellen O'Connell. The Power & Purpose of International Law: Insights from the Theory & Practice of Enforcement (OUP 2008) 249. or error.In the context of self-defence, cf. Oil Platforms (Islamic Republic of Iran v. United States of America), ICJ, Judgement (2003) para 73. Mistakes and involuntary acts may constitute unlawful use of force. See also François Delerue, Cyber Operations and International Law (CUP 2020) 305.
Specifically with respect to countermeasures, the law of State responsibility is based on an objective standard.ILC Articles on State Responsibility, Commentary to Art. 49, para 3. A State resorting to countermeasures does so at its own risk and on the basis of its unilateral assessment of the situation. An incorrect assessment, including in the event of misattribution of malicious cyber operations,ILC Articles on State Responsibility, Art. 4; Tallinn Manual 2.0, Commentary, Rule 20, para. 16. may result in the commission of a wrongful act by the State resorting to countermeasures for which that State would be internationally responsible.ILC Articles on State Responsibility, Commentary to Art. 49, para 3; François Delerue, Cyber Operations and International Law (CUP 2020) 438.
== Appendixes ==
=== See also ===
* Scenario 21: Misattribution caused by deception
=== Notes and references ===
=== Bibliography and further reading ===
Category:Mistake of fact
Category:Legal concepts