Czech Republic Position paper on the application of international law in cyberspace UN Charter and a fundamental rule of customary international law,17 which is also considered as peremptory norm of general international law (jus cogens).18 25. The prohibition of the threat or use of force contained in the UN Charter is deliberately general and encompasses any means and methods used (whether kinetic or cyber means).19 Thus, the prohibition of the threat or use of force applies also in cyberspace. 26. Given the dependency of all States and societies on ICTs, cyber activities can have serious consequences not only in cyberspace but also in the physical world. Such activities can result in malfunction of critical infrastructure, physical damage or extensive economic loss, threaten national security or put human lives into jeopardy. The Czech Republic is of the opinion that cyber operation conducted in cyberspace could amount to the use of force under Article 2(4) of the UN Charter when the effects of the operation are comparable to those of a conventional character. 27. The UN Charter does not provide a definition of the term “use of force”. Whether activities in cyberspace, attributable to a State under international law, violate the prohibition of the threat or use of force as contained in Article 2(4) of the UN Charter needs to be assessed on case-by-case basis. Activities conducted by cyber means that do not amount to a threat or use of force may still amount to a violation of sovereignty or a prohibited intervention into internal or external affairs. In the context of cyber operations, the Czech Republic is of the view that factors offered by the Tallinn Manual 2.0, such as severity, immediacy, directness, invasiveness, measurability of effects, military character, State involvement or presumptive legality of the cyber operation in question represent important criteria in the process of evaluation when deciding whether an act may be characterized as an unlawful use of force.20 28. Depending on the facts and circumstances, cyber operations attributable to a State and amounting to an unlawful use of force under Article 2(4) of the UN Charter may also constitute an "armed attack", under Article 51 of the UN Charter. The term "use of force" is generally perceived to be a broader concept than "armed attack", which is considered as the most grave form of the use of force.21 29. The UN Charter does not provide a definition of the term "armed attack", nor does it list the criteria for determining under what conditions an act amounts to an "armed attack". In accordance with the general guidance provided by the International Court of Justice there are two main factors to be considered when assessing whether a use of force constitutes an armed attack: the scale and 17 See paras 188-190 of the Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment of 27 June 1986, ICJ Reports 1986. 18 Article 53 and Article 64 of the Vienna Convention on the Law of Treaties, concluded 23 May 1969, entered into force 27 January 1980, 1155 UNTS 331. 19 As stated by the International Court of Justice in the Advisory opinion on the Legality of the Threat or Use of Nuclear Weapons, 8 July 1996, ICJ reports 1996, para 39: that Article 2 para 4 of the UN Charter (the prohibition of threat or use of force) “apply to any use of force, regardless the weapons employed. The Charter neither expressly prohibits, nor permits the use of any specific weapon.” 20 See p. 333 – 335 of the Tallinn Manual 2.0. 21 See para 191 of the Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment of 27 June 1986, ICJ Reports 1986. 8