1 In order to avoid confusion, a note is made at this point to clarify two terminologies, “law of armed conflict” (LOAC) and “international humanitarian law”. There are some concerns about the inaccurate use of these two terms. Some think they have essentially the same meaning and can be used interchangeably, e.g. “the law of armed conflict, also known as international humanitarian law, includes principles such as distinction between military and civilian targets” (International Committee of the Red Cross (ICRC), The Law of Armed Conflict: Basic Knowledge, Geneva, June 2002, p. 2, available at: www.icrc.org/eng/assets/files/other/law1_final.pdf), while others render “international humanitarian law” as a potentially narrower concept that relates only to the laws in armed conflict that are designed to regulate the treatment of persons – civilian or military, wounded or active – in armed conflicts (Mary O'Connell, “Historical Development and Legal Basis”, in Dieter Fleck (ed.), The Handbook of International Humanitarian Law, 3rd ed., Oxford University Press, Oxford, 2013, p. 11). There are also some critiques regarding the melding of battlefield laws and humanitarian goals, e.g. “a possible disadvantage of the term [IHL] is that it could be thought to exclude some parts of the laws of war (such as the law on neutrality) whose primary purpose is not humanitarian” (Jean Pictet, Humanitarian Law and the Protection of War Victims, A. W. Sijthoff, Leiden, 1975, p. 11). The International Law Commission distinguishes between LOAC and IHL, with the former governing the conduct and consequences of armed conflict while the latter forms part of the former and constitutes the lex specialis governing the conduct of hostilities (para. 4 of the Commentary to Art. 2 of the Draft Articles on the Effects of Armed Conflicts on Treaties, ILC Yearbook, Vol. 2, Part 2, 2011). For more detailed discussion on the terminology, see Gary D. Solis, The Law of Armed Conflict: International Humanitarian Law in War, Cambridge University Press, Cambridge and New York, 2010, pp. 22–26. Chinese textbooks and papers generally hold the view that the term IHL has evolved from the law of war or LOAC, and thus treat them as synonymous; see, for example, 朱文奇, 何谓国际人道法, 武大国际法评论, 2003, 1 (Wenqi Zhu, “What Is International Humanitarian Law?”, Wuhan University International Law Review, Vol. 1, 2003, only available in Chinese). For the purpose of this paper, the term “IHL” will be used generally, while the term “law of armed conflict” is used when the cited sources use that particular term.

2 See, for example, Zhang, Li, “A Chinese Perspective on Cyber War”, International Review of the Red Cross, Vol. 94, No. 886, 2012, p. 804CrossRefGoogle Scholar, available at: https://international-review.icrc.org/sites/default/files/irrc-886-zhang.pdf (all internet references were accessed in January 2021); Longdi Xu, “The Applicability of the Laws of War to Cyberspace: Exploration and Contention”, 2014, p. 7, available at: www.gov.uk/government/publications/the-applicability-of-the-laws-of-war-to-cyberspace-exploration-and-contention; Chris Wu, “An Overview of the Research and Development of Information Warfare in China”, in Edward Halpin, Philippa Trevorrow, David Webb and Steve Wright (eds), Cyberwar, Netwar and the Revolution in Military Affairs, Palgrave Macmillan, London, 2006; 朱莉欣, 信息网络战的国际法问题研究, 河北法学, 2009, 27(01) (Lixin Zhu, “Research on the International Law of Information Network Operations”, Hebei Law Science, Vol. 27, No. 1, 2009, only available in Chinese); 姜世波, 网络攻击与战争法的适用, 武大国际法评论, 2013, 16(02) (Jiang, Shibo, “War by Internet Cyber Attack and the Application of the Law of War”, Wuhan University International Law Review, Vol. 16, No. 2, 2013Google Scholar, only available in Chinese); 李伯军, 论网络战及战争法的适用问题, 法学评论, 2013, 31(04) (Bojun Li, “On Cyber Warfare and the Application of the Law of War”, Law Review, Vol. 31, No. 4, 2013, only available in Chinese); 朱莉欣, 平战结合与网络空间国际规则制定, 信息安全与通信保密, 2018(07) (Zhu, Lixin, “Competition for International Rules in Cyberspace under the Combination of Peacetime and Wartime”, Information Security and Communications Privacy, No. 7, 2018Google Scholar).

3 王海平, 武装冲突法研究进展及需要关注的问题, 当代法学, 2012, 26(05) (Wang, Haiping, “The Research Progress of the Law of Armed Conflict and the Issues Needing Attention”, Contemporary Law Review, Vol. 26, No. 5, 2012Google Scholar, only available in Chinese); 李莉, 鲁笑英.浅析信息化战争条件下武装冲突法所面临的问题, 西安政治学院学报, 2012, 25(01) (Li, Li and Lu, Xiaoying, “A Brief Analysis of the Problems Faced by the Law of Armed Conflict under the Condition of Information-Based Warfare”, Journal of Xi'an Politics Institute of PLA, Vol. 25, No. 1, 2012Google Scholar, only available in Chinese); 朱雁新, 计算机网络攻击之国际法问题研究, 中国政法大学, 2011 (Yanxin Zhu, “The Research on the International Issues of Computer Network Attack”, doctoral diss., China University of Political Science and Law, 2011, only available in Chinese); 张天舒, 从 “塔林手册” 看网络战争对国际法的挑战, 西安政治学院学报, 2014, 27(01) (Tianshu Zhang, “The Challenges of Cyber Warfare to International Law: From the Perspective of The Tallinn Manual on the International Law Applicable to Cyber Warfare”, Journal of Xi'an Politics Institute of PLA, Vol. 27, No. 1, 2014, only available in Chinese).

4 James J. Wirtz, “The Cyber Pearl Harbor”, Intelligence and National Security, Vol. 32, No. 6, 2017; James J. Wirtz, “The Cyber Pearl Harbor Redux: Helpful Analogy or Cyber Hype?”, Intelligence and National Security, Vol. 33, No. 5, 2018; US Department of Defense (DoD), “Remarks by Secretary Panetta on Cybersecurity to the Business Executives for National Security, New York City”, 12 October 2012, available at: https://content.govdelivery.com/accounts/USDOD/bulletins/571813.

5 In this article, the term “cyber warfare” is understood as “means and methods of warfare that rely on information technology and are used in the context of an armed conflict”. See Jakob Kellenberger, “International Humanitarian Law and New Weapon Technologies, 34th Round Table on Current Issues of International Humanitarian Law, Sanremo, Italy, 8–10 September 2011: Keynote Address by Dr Jakob Kellenberger”, International Review of the Red Cross, Vol. 94, No. 886, 2012, available at: https://international-review.icrc.org/sites/default/files/irrc-886-kellenberger-spoerri.pdf. For some Chinese scholars, cyber warfare is a special form of information warfare and is a new means or method of warfare. Information warfare refers to a series of hostile activities carried out by belligerent parties in order to maintain their right to acquire, control and use information. Its connotation and extension are broader than cyber warfare and can include cyber warfare, intelligence warfare, electronic warfare, psychological warfare, etc. Cyber warfare refers to the process of disrupting, destroying or threatening the other belligerent parties’ information and network systems while ensuring the security of one's own information and network systems through computer networks. See, for example, B. Li, above note 2. Some argue that the main question expressed by the concept of cyber warfare is whether cyber attackers “armed” with keyboards, computer viruses and malware can become (or have become) a new means or method of warfare. See 黄志雄主编, 网络空间国际规则新动向: “塔林手册 2.0 版” 研究文集, 社会科学文献出版社, 2019: 301 (Zhixiong Huang (ed.), New Trends in International Rules for Cyberspace: Collection of Papers on Tallinn Manual 2.0, Social Sciences Academic Press, China, 2019, p. 301); 黄志雄, 国际法视角下的 “网络战” 及中国的对策——以诉诸武力权为中心, 现代法学, 2015, 37(05) (Zhixiong Huang, “International Legal Issues concerning ‘Cyber Warfare’ and Strategies for China: Focusing on the Field of Jus ad Bellum”, Modern Law Science, Vol. 37, No. 5, 2015).

6 See ICRC, “War and Law”, available at: www.icrc.org/en/war-and-law.

7 See UN GGE, Report of the Group of Governmental Experts on Developments in the Field of Information and Telecommunications in the Context of International Security, UN Doc. A/70/174, 22 July 2015, para. 28, available at: www.un.org/ga/search/view_doc.asp?symbol=A/70/174.

8 Ibid.

9 Michael N. Schmitt and Liis Vihul, “International Cyber Law Politicized: The UN GGE's Failure to Advance Cyber Norms”, Just Security, 30 June 2017, available at: www.justsecurity.org/42768/international-cyber-law-politicized-gges-failure-advance-cyber-norms/.

10 See, for example, ibid.; Arun Mohan Sukumar, “The UN GGE Failed. Is International Law in Cyberspace Doomed as Well?”, Lawfare, 4 July 2017, available at: https://lawfareblog.com/un-gge-failed-international-law-cyberspace-doomed-well.

11 See “The United Nations Doubles Its Workload on Cyber Norms, and Not Everyone Is Pleased”, Council on Foreign Relations Blog, 15 November 2018, available at: www.cfr.org/blog/united-nations-doubles-its-workload-cyber-norms-and-not-everyone-pleased. The two resolutions are sponsored by Russia (UN Doc. A/C.1/73/L.27/Rev.1) and the United States (UN Doc. A/C.1/73/L.37) respectively.

12 Geneva Convention (III) relative to the Treatment of Prisoners of War of 12 August 1949, 75 UNTS 135 (entered into force 21 October 1950) (GC III), Art. 4(A)(2); Protocol Additional (I) to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts, 1125 UNTS 3, 8 June 1977 (entered into force 7 December 1978) (AP I), Art. 44(3); Jean-Marie Henckaerts and Louise Doswald-Beck (eds), Customary International Humanitarian Law, Vol. 1: Rules, Cambridge University Press, Cambridge, 2005 (ICRC Customary Law Study), pp. 14–17, available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1.

13 Heather Harrison Dinniss, “Participants in Conflict – Cyber Warriors, Patriotic Hackers and the Laws of War”, in Dan Saxon (ed.), International Humanitarian Law and the Changing Technology of War, Martinus Nijhoff, Boston, MA, and Leiden, 2013, p. 256; Heather Harrison Dinniss, Cyber Warfare and the Laws of War, Cambridge University Press, Cambridge, 2012, p. 145.

14 The ICRC Customary Law Study, above note 12, Rule 6, stipulates that civilians are protected against attack unless and for such time as they take a direct part in hostilities. For substantive discussion about “direct participation in hostilities”, see Nils Melzer, Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law, ICRC, Geneva, 2009 (Interpretive Guidance).

15 For a detailed description of the cyber attack against Estonia in 2007, see “Cyber Attacks against Estonia (2007)”, International Cyber Law in Practice: Interactive Toolkit, NATO Cooperative Cyber Defence Centre of Excellence (CCD COE), available at: https://cyberlaw.ccdcoe.org/wiki/Cyber_attacks_against_Estonia_(2007); Eneken Tikk, Kadri Kaska and Liis Vihul, International Cyber Incidents: Legal Considerations, CCD COE, Tallinn, 2010, pp. 15–16, 31.

16 Chinese Academy of Cyberspace Studies (ed.), China Internet Development Report 2017, Springer, Berlin, 2019, p. 107; 国家互联网应急中心, 2020 年上半年我国互联网网络安全监测数据分析报告, 2020 (National Computer Network Emergency Response Technical Team/Coordination Centre of China, Analysis Report of China's Internet Network Security Monitoring Data in the First Half of 2020, 2020, only available in Chinese), available at: https://tinyurl.com/y2lpzdh4; Ministry of Foreign Affairs of the People’ Republic of China, “Foreign Ministry Spokesperson Wang Wenbin's Regular Press Conference on September 29, 2020”, available at: https://tinyurl.com/y4xolw3g.

17 China's date of ratification/accession to the Geneva Conventions is 28 December 1956. See the ICRC Treaty Database, available at: https://ihl-databases.icrc.org/applic/ihl/ihl.nsf/vwTreatiesByCountrySelected.xsp?xp_countrySelected=CN.

18 China's date of ratification/accession to AP I and AP II is 14 September 1983. See ibid.

19 Binxin Zhang, “Cyberspace and International Humanitarian Law: The Chinese Approach”, in Suzannah Linton, Tim McCormack and Sandesh Sivakumaran (eds), Asia-Pacific Perspectives on International Humanitarian Law, Cambridge University Press, Cambridge, 2019, p. 323.

20 See “China's Submissions to the Open-ended Working Group on Developments in the Field of Information and Telecommunications in the Context of International Security”, p. 6, available at: www.un.org/disarmament/wp-content/uploads/2019/09/china-submissions-oewg-en.pdf.

21 Ibid.

22 AALCO, Verbatim Record of Discussions: Fifty-Eighth Annual Session, AALCO/58/DAR ES SALAAM/2019/VR, Dar es Salaam, 21–25 October 2019, available at: www.aalco.int/Final%20Verbatim%202019.pdf.

23 AALCO, Verbatim Record of Discussions: Fifty-Fourth Annual Session, AALCO/54/BEIJING/2015/VR, Beijing, 13–17 April 2015.

24 Xinmin Ma, “What Kind of Internet Order Do We Need?”, Chinese Journal of International Law, Vol. 14, No. 2, 2015. Xinmin Ma served as deputy director of the Department of Treaty and Law of the Ministry of Foreign Affairs of China from 2014 to 2019.

25 AALCO, Verbatim Record of Discussions: Fifty-Fifth Annual Session, AALCO/55/NEW DELHI (HEADQUARTERS)/2016/VR, New Delhi, 17–20 May 2016.

26 For more explanation on China's attitude towards IHL, see B. Zhang, above note 19.

27 ICJ, Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 8 July 1996, ICJ Reports 1996, p. 266.

28 AP I, Art. 48; ICRC Customary Law Study, above note 12, Rules 1, 7, pp. 3, 25.

29 AP I, Art. 51(4); ICRC Customary Law Study, above note 12, Rule 11, p. 37.

30 See Marco Rossini, Cyber Operations and the Use of Force in International Law, Oxford University Press, Oxford, 2014, pp. 178–182; William H. Boothby, “Where Do Cyber Hostilities Fit in the International Law Maze?”, in Hitoshi Nasu and Robert McLaughlin (eds), New Technologies and the Law of Armed Conflict, Springer, Berlin, 2014, pp. 60–62; Knut Dörmann, “Applicability of the Additional Protocols to Computer Network Attacks”, paper presented at the International Expert Conference on Computer Network Attacks and the Applicability of International Humanitarian Law, Stockholm, 17–19 November 2004; Droege, Cordula, “Get Off My Cloud: Cyber Warfare, International Humanitarian Law, and the Protection of Civilians”, International Review of the Red Cross, Vol. 94, No. 886, 2012CrossRefGoogle Scholar; Schmitt, Michael N., “The Law of Cyber Warfare: Quo Vadis?”, Stanford Law and Policy Review, Vol. 25, No. 2, 2014Google Scholar.

31 Michael N. Schmitt (ed.), Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations, Cambridge University Press, Cambridge, 2017 (Tallinn Manual 2.0), Rule 92, p. 415.

32 The consequence-based approach is very useful as it switches the focus from the means and nature of an act to the effect and consequence of an act, thus fulfilling the requirement of “violence” and keeping the provision dynamic and evolutive. However, the present authors still have two concerns. The first is that from a practical perspective, the assessment of the damage turns out to be extremely tricky, especially when the consequences are mostly indirect. The second concern is that the consequence-based approach limits the notion of attack so as to exclude those operations that result in severe and disruptive non-physical harm. Similar concerns can be found in ICRC, International Humanitarian Law and Cyber Operations during Armed Conflicts, Geneva, November 2019 (ICRC Cyber Operations Paper), pp. 7–8. The ICRC has also mentioned that an overly restrictive understanding of the notion of attack would be difficult to reconcile with the object and purpose of the rules on the conduct of hostilities, which is to ensure the protection of the civilian population and civilian objects against the effects of hostilities. See ICRC, International Humanitarian Law and the Challenges of Contemporary Armed Conflicts, 32IC/15/11, October 2015 (ICRC Challenges Report 2015), p. 41.

33 See Kelsey, Jeffrey, “Hacking into International Humanitarian Law: The Principles of Distinction and Neutrality in the Age of Cyber Warfare”, Michigan Law Review, Vol. 106, No. 7, 2008, pp. 1429–1430Google Scholar.

34 Geiss, Robin and Lahmann, Henning, “Cyber Warfare: Applying the Principle of Distinction in an Interconnected Space”, Israel Law Review, Vol. 45, No. 3, 2012, pp. 381, 383CrossRefGoogle Scholar.

35 The principle of distinction provides that only military objectives may be directly targeted in armed conflict. However, an attack on a legitimate military objective may sometimes cause incidental damage to civilian persons or objects. These harmful side effects are regulated by the principle of proportionality, which prohibits attacks that may be expected to cause injury to civilian life or property that is excessive in relation to the anticipated military advantage. A clear statement of the principle of proportionality can be found in AP I, Art. 51(5)(b). See also Jonathan Crowe and Kylie Weston-Scheuber, Principles of International Humanitarian Law, Edward Elgar, Cheltenham, 2013, pp. 55–57.

36 “Civilians play an increasingly important and complex role in armed conflicts, both as victims and perpetrators.” This overall trend is called “civilianization” in Andreas Wenger and Simon J. A. Mason, “The Civilianization of Armed Conflict: Trends and Implications”, International Review of Red Cross, Vol. 90, No. 872, 2008.

37 L. Zhu, “Competition for International Rules in Cyberspace”, above note 2, p. 40.

38 State Council Information Office of the People's Republic of China (SCIO), China's National Defense in the New Era, Beijing, July 2019, available at: www.scio.gov.cn/zfbps/32832/Document/1660325/1660325.htm; SCIO, China's Military Strategy, Beijing, May 2015, available at: www.scio.gov.cn/zfbps/ndhf/2015/Document/1435159/1435159.htm.

39 See ICRC Cyber Operations Paper, above note 32, pp. 8–9.

40 See, for example, J. Kelsey, above note 33, p. 1427; Yoram Dinstein, “The Principle of Distinction and Cyber War in International Armed Conflicts”, Journal of Conflict and Security Law, Vol. 17, No. 2, 2012, p. 261; Michael N. Schmitt, “Wired Warfare: Computer Network Attack and Jus in Bello”, International Review of the Red Cross, Vol. 84, No. 846, 2002, p. 365.

41 DoD, Law of War Manual, Washington, DC, 12 June 2015, pp. 985–999.

42 Danish Ministry of Defence, Defence Command Denmark, Military Manual on International Law Relevant to Danish Armed Forces in International Operations, Copenhagen, September 2016.

43 AP I, Art. 51(4).

44 陈鹏飞, 论当代武装冲突法面临的挑战, 西安政治学院学报, 2014, 27(05) (Chen, Pengfei, “Analysis of the Challenges to Contemporary Armed Conflict Law”, Journal of Xi'an Politics Institute of PLA, Vol. 27, No. 5, 2014Google Scholar, only available in Chinese).

45 AP I, Art. 51(2); ICRC Customary Law Study, above note 12, Rule 6, pp. 19–24.

46 Yoram Dinstein, The Conduct of Hostilities under the Law of International Armed Conflict, Cambridge University Press, Cambridge, 2016, p. 174.

47 AP I, Art. 51(3); ICRC Customary Law Study, above note 12, Rule 6, pp. 20–21; Interpretive Guidance, above note 14, pp. 41–68.

48 GC III, Art. 4A(6); ICRC Customary Law Study, above note 12, Rule 106, pp. 386–387, and in particular Rule 5, which explains that members of a levée en masse are an exception to the definition of civilians in that although they are not members of the armed forces, they qualify as combatants.

49 GC III, Art. 4A(6).

50 Tallinn Manual 2.0, above note 31, Rule 88, p. 409.

51 Elizabeth Mavropoulou, “Targeting in the Cyber Domain: Legal Challenges Arising from the Application of the Principle of Distinction to Cyber Attacks”, Journal of Law and Cyber Warfare, Vol. 4, No. 2, 2015, p. 78.

52 David Turns, “Cyber Warfare and the Notion of Direct Participation in Hostilities”, Journal of Conflict and Security Law, Vol. 17 No. 2, 2012, p. 292; see also Michael N. Schmitt, “‘Direct Participation in Hostilities’ and 21st Century Armed Conflict”, in Horst Fischer and Dieter Fleck (eds), Crisis Management and Humanitarian Protection: Festschrift for Dieter Fleck, BWV, Berlin, 2004, p. 527.

53 Y. Dinstein, above note 46, p. 44.

54 AP I, Art. 43(2).

55 H. Harrison Dinniss, “Participants in Conflict”, above note 13, p. 254.

56 AP I, Art. 50(1); ICRC Customary Law Study, above note 12, Rule 5, pp. 17–19.

57 Vijay M. Padmanabhan, “Cyber Warriors in the Jus in Bello”, International Law Studies, Vol. 89, 2013; Maurizio D'Urso, “The Cyber Combatant: A New Status for a New Warrior”, Philosophy and Technology, Vol. 28, No. 3, 2015; Jake B. Sher, “Anonymous Armies: Modern ‘Cyber-Combatants’ and Their Prospective Rights under International Humanitarian Law”, Pace International Law Review, Vol. 28, No. 1, 2016; Sean Watts, “The Notion of Combatancy in Cyber Warfare”, paper presented at the 4th International Conference on Cyber Conflict, Tallinn, 5–8 June 2012.

58 Donald Trump, “Statement by President Donald J. Trump on the Elevation of Cyber Command”, 18 August 2017, available at: www.whitehouse.gov/briefings-statements/statement-president-donald-j-trump-elevation-cyber-command/.

59 UN, Developments in the Field of Information and Telecommunications in the Context of International Security: Report of the Secretary-General, UN Doc. A/67/167, 23 July 2012, p. 5.

60 Y. Dinstein, above note 46, p. 41.

61 H. Harrison Dinniss, Cyber Warfare, above note 13, p. 144.

62 Geneva Convention (I) for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field of 12 August 1949, 75 UNTS 31 (entered into force 21 October 1950), Art. 13(2); Geneva Convention (II) for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea of 12 August 1949, 75 UNTS 85 (entered into force 21 October 1950), Art. 13(2); GC III, Art. 4(A)(2); Geneva Convention (IV) relative to the Protection of Civilian Persons in Time of War of 12 August 1949, 75 UNTS 287 (entered into force 21 October 1950), Art. 4(2); H. Harrison Dinniss, Cyber Warfare, above note 13, p. 145.

63 GC III, Art. 4A(6); H. Harrison Dinniss, Cyber Warfare, above note 13, p. 145.

64 Y. Dinstein, above note 46, p. 39; International Criminal Tribunal for Rwanda (ICTR), The Prosecutor v. Jean-Paul Akayesu, Case No. ICTR-96-4-T, Judgment (Trial Chamber), 2 September 1998, para. 626.

65 Marco Roscini, Cyber Operations and the Use of Force in International Law, Oxford University Press, Oxford, 2014, p. 195.

66 Tilman Rodenhäuser, Organizing Rebellion: Non-State Armed Groups under International Humanitarian Law, Human Rights Law, and International Criminal Law, Oxford University Press, Oxford, 2018, pp. 104–108.

67 H. Harrison Dinniss, Cyber Warfare, above note 13, p. 149.

68 Y. Dinstein, above note 46, p. 54.

69 See Denise Bindschedler-Robert, “A Reconsideration of the Law of Armed Conflicts”, in The Law of Armed Conflicts: Report of the Conference on Contemporary Problems of the Law of Armed Conflict, 1971, p. 40; Katherine Del Mar, “The Requirement of ‘Belonging’ under International Humanitarian Law”, European Journal of International Law, Vol. 21, No. 1, 2010.

70 H. Harrison Dinniss, “Participants in Conflict”, above note 13, p. 262.

71 The effective control standard elaborated by the ICJ in Nicaragua appears inappropriate to define what “belonging to a party to the conflict” means, as, unlike the overall control and complete dependency standards, it expresses control over the act and not over the actor and thus focuses on specific activities. Marko Milanović, “State Responsibility for Acts of Non-State Actors: A Comment on Griebel and Plücken”, Leiden Journal of International Law, Vol. 22, No. 2, 2009, p. 317. On the meaning of the effective control, overall control and complete dependency standards, see Antonio Cassese, “The Nicaragua and Tadić Tests Revisited in Light of the ICJ Judgment on Genocide in Bosnia”, European Journal of International Law, Vol. 18 No. 4, 2007.

72 Y. Dinstein, above note 46, p. 37.

73 The Internet is constantly searched by millions of software bots intent on finding connected computers; a bot searching for military-designated IP addresses would be able to find them in a matter of minutes. Once identified, the only way to effectively move the computer or system out of range is to disconnect it, a solution which is likely to disrupt its normal running and/or usefulness; thus, any system remaining connected to the network in any way would be solely reliant on its electronic defences to prevent intrusions and defend against them. So, while initially the idea of displaying signs on computers or systems appears a useful solution, in practice it creates an imbalance between the purpose of the requirement of displaying signs and the ability of the military to conduct operations. See H. Harrison Dinniss, “Participants in Conflict”, above note 13, p. 257; H. Harrison Dinniss, Cyber Warfare, above note 13, pp. 145–149.

74 Tallinn Manual 2.0, above note 31, Rule 87, p. 405.

75 This is not always the case; for example, civilians who directly participate in hostilities can be attacked, but they are hardly likely to wear military uniforms.

76 See Prashant Mali, “Defining Cyber Weapon in Context of Technology and Law”, in Information Management Association, Multigenerational Online Behavior and Media Use: Concepts, Methodologies, Tools, and Applications, IGI Global, Hershey, PA, 2019; Jeffrey T. Biller and Michael N. Schmitt, “Classification of Cyber Capabilities and Operations as Weapons, Means, or Methods of Warfare”, International Law Studies, Vol. 95, 2019; H. Harrison Dinniss, Cyber Warfare, above note 13, pp. 250–278.

77 H. Harrison Dinniss, Cyber Warfare, above note 13, p. 148.

78 Interpretive Guidance, above note 14, p. 46.

79 L. Zhu, “Competition for International Rules in Cyberspace”, above note 2, p. 40.

80 M. N. Schmitt, above note 52, p. 527.

81 AP I, Art. 50(1); ICRC Customary Law Study, above note 12, Rule 6, pp. 23–24.

82 AP I, Art. 51(3); Protocol Additional (II) to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of Non-International Armed Conflicts, 1125 UNTS 609, 8 June 1977 (entered into force 7 December 1978), Art. 13(3); ICRC Customary Law Study, above note 12, Rule 6, pp. 19–24.

83 H. Harrison Dinniss, “Participants in Conflict”, above note 13, p. 258.

84 D. Turns, above note 52, p. 279.

85 AP I, Art. 51(3).

86 Judith G. Gardam, Non-Combatant Immunity as a Norm of International Law, Martinus Nijhoff, Dordrecht, 1993.

87 Michael Bothe, Karl Josef Partsch and Waldemar A. Solf, New Rules for Victims of Armed Conflicts: Commentary to the Two 1977 Protocols Additional to the Geneva Conventions of 1949, Martinus Nijhoff, Dordrecht, 1982, pp. 301–304.

88 Israel High Court of Justice, Public Committee against Torture in Israel v. Israel et al., Case No. HCJ 769/02, Judgment, 11 December 2005 (Targeted Killings).

89 Interpretive Guidance, above note 14, p. 46.

90 “Forum: Direct Participation in Hostilities: Perspectives on the ICRC Interpretive Guidance”, New York University Journal of International Law and Politics, Vol. 42, No. 3, 2010.

91 D. Turns, above note 52, p. 285.

92 Israel High Court of Justice, Targeted Killings, above note 88, para. 33.

93 Interpretive Guidance, above note 14, p. 46.

94 Ibid., p. 48.

95 This three-part test has also been adopted for application to cyber warfare in the Tallinn Manual 2.0, above note 31, pp. 429–430.

96 “Cyber Attacks against Estonia (2007)”, above note 15; E. Tikk, K. Kaska and L. Vihul, above note 15, pp. 14–33.

97 “Stuxnet (2010)”, International Cyber Law in Practice: Interactive Toolkit, CCD COE, available at: https://cyberlaw.ccdcoe.org/wiki/Stuxnet_(2010); E. Tikk, K. Kaska and L. Vihul, above note 15, pp. 66–89.

98 D. Turns, above note 52, p. 286.

99 ICRC Challenges Report 2015, above note 32, p. 42.

100 A report shows that between the end of 2009 and early 2010, about 1,000 centrifuges at a fuel enrichment plant facility in Natanz, Iran, had to be replaced, implying that those centrifuges were broken. David Albright, Paul Brannan and Christina Walrond, Did Stuxnet Take Out 1,000 Centrifuges at the Natanz Enrichment Plant?, Institute for Science and International Security, 22 December 2010; “Stuxnet (2010)”, above note 97.

101 Tallinn Manual 2.0, above note 31, p. 429.

102 Interpretive Guidance, above note 14, p. 53.

103 Bin Cheng, General Principles of Law as Applied by International Courts and Tribunals, Cambridge University Press, Cambridge, 1987, p. 181.

104 See Emily Crawford, Virtual Battlegrounds: Direct Participation in Cyber Warfare, Sydney Law School Research Paper No. 12/10, 8 February 2012, available at: https://ssrn.com/abstract=2001794.

105 See Lockheed Martin, “Gaining the Advantage, Applying Cyber Kill Chain Methodology to Network Defense”, 2015, available at: www.lockheedmartin.com/content/dam/lockheed-martin/rms/documents/cyber/Gaining_the_Advantage_Cyber_Kill_Chain.pdf.

106 Ibid.

107 Interpretive Guidance, above note 14, p. 46.

108 ICRC, Fourth Expert Meeting on the Notion of Direct Participation in Hostilities: Summary Report, Geneva, 27–28 November 2006, p. 48. The present authors note that some doubts were expressed as to whether this assessment could be upheld in extreme situations – namely, those in which the expertise of a particular civilian is of very exceptional and potentially decisive value for the outcome of an armed conflict, such as the case of nuclear weapons experts during the Second World War.

109 AP I, Art. 51(3); ICRC Customary Law Study, above note 12, Rule 6, pp. 19–24.

110 Interpretive Guidance, above note 14, p. 73.

111 Ibid., pp. 70–71.

112 Israel High Court of Justice, Targeted Killings, above note 88, para. 40.

113 Interpretive Guidance, above note 14, pp. 70–71.

114 See the description of direct participation in hostilities as potentially “intermittent and discontinuous” in ICTR, The Prosecutor v. Strugar, Case No. IT-01-42-A, Judgment (Appeals Chamber), 17 July 2008, para. 178.

115 Supreme Court of Israel, Public Committee against Torture in Israel v. Government of Israel, Case No. HCJ 769/02, 13 December 2006, para. 39.

116 Ibid., para. 39; Daniel Statman, “Targeted Killing”, Theoretical Inquiries in Law, Vol. 5, No. 1, 2004, pp. 179, 195.

117 The present authors try not to use the term “objects” here because the question about whether there are non-human targets which are not “objects” will be discussed in the following paragraphs.

118 AP I, Art. 52(1); ICRC Customary Law Study, above note 12, Rule 9, pp. 31–32.

119 AP I, Art. 52(2); ICRC Customary Law Study, above note 12, Rule 7, pp. 24–28.

120 AP I, Art 52(2); ICRC Customary Law Study, above note 12, Rule 8, pp. 29–32; Jacob Kellenberger, “International Humanitarian Law at the Beginning of the 21st Century”, statement given at the 26th Round Table on Current Problems in International Humanitarian Law, Sanremo, 5–7 September 2002.

121 DoD, above note 41, p. 210; Charles J. Dunlap, “The End of Innocence: Rethinking Non-Combatancy in the Post-Kosovo Era”, Strategic Review, Vol. 9, 2000, p. 17; US Department of the Navy and Department of Homeland Security, The Commander's Handbook on the Law of Naval Operations, July 2007, para. 8.2. There are also some opposite views, such as Laurent Gisel, “The Relevance of Revenue-Generating Objects in Relation to The Notion of Military Objective”, in ICRC, The Additional Protocols at 40: Achievements and Challenges, 18th Bruges Colloquium, 19–20 October 2017.

122 Program on Humanitarian Policy and Conflict Research at Harvard University, HPCR Manual on International Law Applicable to Air and Missile Warfare, Cambridge, MA, 2010, p. 49.

123 Yves Sandoz, Christophe Swinarski and Bruno Zimmermann (eds), Commentary on the Additional Protocols, ICRC, Geneva, 1987 (ICRC Commentary on APs), para. 2018.

124 E. Mavropoulou, above note 51, p. 44.

125 Marco Sassòli, “Military Objectives”, in Max Planck Encyclopedia of Public International Law, 2015, para. 7.

126 J. Kelsey, above note 33, p. 1440.

127 M. Roscini, above note 65, p. 186.

128 ICRC Commentary on APs, above note 123, para. 2019.

129 Robert Kolb and Richard Hyde, An Introduction to the International Law of Armed Conflicts, Hart Publishing, Oxford, 2008, pp. 60, 131.

130 ICRC Commentary on APs, above note 123, para. 2024.

131 Ibid., paras 2024–2025.

132 M. Roscini, above note 65, p. 188.

133 R. Geiss and H. Lahmann, above note 34, p. 388.

134 Ibid.

135 Marco Roscini, “Military Objectives in Cyber Warfare”, in Mariarosaria Taddeo and Luciano Floridi (eds), Ethics and Policies for Cyber Operations: A NATO Cooperative Cyber Defence of Excellence Initiative, Springer, Cham, 2017, p. 108; Katharina Ziolkowski, Stuxnet – Legal Considerations, CCD COE, Tallinn, 2012, p. 5, available at: https://ccdcoe.org/uploads/2018/10/Ziolkowski_Stuxnet2012-LegalConsiderations.pdf.

136 Dominik Steiger, “Civilian Objects”, in Max Planck Encyclopedia of Public International Law, 2011, para. 12.

137 Ibid.

138 R. Geiss and H. Lahmann, above note 34, p. 385.

139 To avoid ambiguity, in terms of the numbers noted, we would like to remind readers that not all government communication is equal to military communication or military objectives.

140 Jensen, Eric Talbot, “Cyber Warfare and Precautions against the Effects of Attacks”, Texas Law Review, Vol. 88, No. 7, 2010, pp. 1522, 1542Google Scholar.

141 R. Geiss and H. Lahmann, above note 34, p. 388.

142 L. Zhu, “Competition for International Rules in Cyberspace”, above note 2, p. 40.

143 International Criminal Tribunal for the former Yugoslavia, Final Report to the Prosecutor by the Committee Established to Review the NATO Bombing Campaign against the Federal Republic of Yugoslavia, 13 June 2000, para. 75.

144 AP I, Arts 51(5)(b), 57(2)(iii).

145 Ibid., Art. 52(3).

146 Tallinn Manual 2.0, above note 31, p. 448.

147 Dinstein, Yoram, “Legitimate Military Objectives under the Current Jus in Bello”, International Law Studies, Vol. 78, 2002, p. 142Google Scholar.

148 Tallinn Manual 2.0, above note 31, Rule 100, p. 437; M. N. Schmitt, above note 30, p. 269; Michael N. Schmitt, “Rewired Warfare: Rethinking the Law of Cyber Attack”, International Review of the Red Cross, Vol. 96, No. 893, 2015, p. 200.

149 ICRC Commentary on APs, above note 123, paras 2007, 2008.

150 See, for example, Kubo Mačák, “Military Objectives 2.0: The Case for Interpreting Computer Data as Objects under International Humanitarian Law”, Israel Law Review, Vol. 48, No. 1, 2015; ICRC Cyber Operations Paper, above note 32, p. 8; ICRC Challenges Report 2015, above note 32, pp. 41–42; ICRC, International Humanitarian Law and the Challenges of Contemporary Armed Conflicts: Recommitting to Protection in Armed Conflict on the 70th Anniversary of the Geneva Conventions, Geneva, 2019 (ICRC Challenges Report 2019), p. 28.

151 Michael N. Schmitt, “International Cyber Norms: Reflections on the Path Ahead”, Netherlands Military Law Review, 17 September 2018, available at: http://puc.overheid.nl/doc/PUC_248171_11;

152 Ibid.; Michael N. Schmitt, “Notion of Objects during Cyber Operations: A Riposte in Defence of Interpretive and Applicative Precision”, Israel Law Review, Vol. 48, No. 1, 2015.

153 As noted in Y. Dinstein, above note 46, pp. 164–174, the principle of precaution includes both active precautions in attack (AP I, Art. 57) and passive precaution (AP I, Art. 58). Active precautions in attack mandate “(a) [d]oing everything feasible to verify that the targets to be attacked are lawful [and] (b) [t]aking all feasible precautions in the choice of means and methods of attack, with a view to avoiding – or, at least, minimizing – collateral damage to civilians and civilian objects”. Passive precaution requires belligerent parties, “‘to the maximum extent feasible’, (i) to endeavour to remove civilians and civilian objects under their control from the vicinity of military objectives; (ii) to avoid locating military objectives within or near densely populated areas; and (iii) otherwise to protect civilians and civilian objects against the dangers resulting from military operations”.

154 Paul Ducheine and Terry Gill, “From Cyber Operations to Effects: Some Targeting Issues”, Netherlands Military Law Review, 17 September 2018, available at: https://puc.overheid.nl/doc/PUC_248377_11/1.

155 K. Mačák, above note 150.

156 AP I, Art. 102: “The original of this Protocol, of which the Arabic, Chinese, English, French, Russian and Spanish texts are equally authentic, …”.

157 K. Mačák, above note 150.

158 The Chinese version of AP I uses the term “物体”. See www.icrc.org/zh/doc/assets/files/other/mt_070116_prot1_c.pdf.

159 “由物质构成的, 占有一定空间的个体”. See 当代汉语词典, 上海辞书出版社, 2001 (Contemporary Chinese Dictionary, Shanghai Dictionary Publishing House, 2001); 现代汉语大词典, 下册, 上海辞书出版社, 2009 (Modern Chinese Dictionary, Vol. 2, Shanghai Dictionary Publishing House, 2009);新华汉语词典, 崇文书局, 2006 (Xinhua Chinese Dictionary, Chongwen Publishing House, 2006); 近现代词源, 上海辞书出版社, 2010 (Etymology of Modern Times, Shanghai Dictionary Publishing House, 2010).

160 Dinniss, Heather Harrison, “The Nature of Objects: Targeting Networks and the Challenge of Defining Cyber Military Objectives”, Israel Law Review, Vol. 48, No. 1, 2015, p. 41Google Scholar.

161 Ibid.

162 Ibid.

163 朱雁新, 数据的性质: 对军事目标法律含义的重新解读, 载黄志雄主编, 网络空间国际规则新动向: “塔林手册2.0版” 研究文集, 社会科学文献出版社, 2019: 410–413 (Yanxin Zhu, “The Nature of Data: A Reinterpretation of the Legal Meaning of Military Objective”, in Zhixiong Huang (ed.), New Trends in International Rules for Cyberspace: Collection of Papers on Tallinn Manual 2.0, Social Sciences Academic Press, China, 2019, pp. 410–413, only available in Chinese).

164 Ibid, p. 410.

165 AP I, Art. 52(2).

166 ICRC Cyber Operations Paper, above note 32, p. 8.

167 Ibid., p. 8.

168 K. Mačák, above note 150.

169 See Vienna Convention on the Law of Treaties, 1155 UNTS 331, 23 May 1969 (entered into force 27 January 1980), Art. 31(3)(a).

170 ICRC Cyber Operations Paper, above note 32, p. 8.

171 ICRC Challenges Report 2019, above note 150, p. 28.

172 See M. N. Schmitt, above note 151.

173 Tallinn Manual 2.0, above note 31, p. 435.

174 M. Bothe, K. J. Partsch and W. A. Solf, above note 87, pp. 301–304.

175 K. Mačák, above note 150.

176 AP I, Art. 52(2).

177 World Economic Forum, “António Guterres: Read the UN Secretary-General's Davos Speech in Full”, 24 January 2019, available at: www.weforum.org/agenda/2019/01/these-are-the-global-priorities-and-risks-for-the-future-according-to-antonio-guterres/.

178 Jiminián, Jimena M. Conde, “The Principle of Distinction in Virtual War: Restraints and Precautionary Measures under International Humanitarian Law”, Tilburg Law Review, Vol. 15, No. 1, 2010CrossRefGoogle Scholar. See also Marco Sassòli, Antoine Bouvier and Anne Quintin, How Does Law Protect in War?, 3^rd ed., Vol. 1, ICRC, Geneva, 2011, p. 52.

179 DoD, above note 4; J. J. Wirtz, “The Cyber Pearl Harbor”, above note 4; J. J. Wirtz, “The Cyber Pearl Harbor Redux”, above note 4.