alleged violations were committed.”18 The ICJ confirmed the effective control test in the Genocide Convention case. 23. Article 11 ARSIWA states that “conduct which is not attributable to a state under the preceding articles shall nevertheless be considered an act of that state under international law if and to the extent that the state acknowledges and adopts the conduct in question as its own.” In the Tehran Hostages case, the ICJ held that state responsibility was engaged with what the Court called, “the seal of official government approval”.19 In a cyber context, a malicious cyber-operation conducted by a third party can thus be attributed to a state where it essentially takes ownership of the act, which might be ascertained through acts of support, approval and/or acquiescence. 24. There is a distinction to be drawn between legal attribution and political attribution. The former is a strictly legal exercise grounded in international law and the rules of state responsibility, while the latter is likely to be informed by political and technical assessments, often heavily based on intelligence reports. It is important to maintain clarity between the different frameworks in which legal attribution and political attribution are to be considered. Countermeasures 25. Under well-established rules of state responsibility, a state responsible for an internationally wrongful act is under an obligation to cease its behaviour and to make full reparation for the injury caused. A state that is the victim of a cyber-operation constituting an internationally wrongful act attributable to another state may respond in various ways, including seeking recourse through dispute resolution mechanisms, where available. Recourse to countermeasures – i.e. measures which would otherwise be unlawful – against the state responsible for the internationally wrongful act to induce compliance is permitted in accordance with the limitations imposed by international law. Countermeasures must inter alia be proportionate and temporary in character and cannot include the use of force. There is no requirement for responsive measures to be similar in kind and in this context therefore they may include non-cyber means. 26. On the question of third party or collective countermeasures, Ireland considers that since the adoption of the ARSIWA in 2001, state practice indicates that such measures are permissible in limited circumstances, in particular in the context of violations of peremptory norms. The possibility of imposing third party or collective countermeasures in the cyber context is particularly relevant for states that may consider it necessary to respond to a malicious cyber-operation with a counter-operation, but lack the technological capacity to do so on their own. 18 Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) Merits Judgment, ICJ Reports 1986, p. 14, [86] [109] and [115]. 19 United States Diplomatic and Consular Staff in Tehran, Judgment, ICJ Reports 1980, p. 3, [73].