1 The natural environment consists of “the natural world together with the system of inextricable interrelations between living organisms and their inanimate environment, in the widest sense possible”. See ICRC, Guidelines on the Protection of the Natural Environment in Armed Conflict, Geneva, 2020 (ICRC Guidelines), p. 17, para. 16. The term “environment” is also used in this article.

2 United Nations Environment Programme (UNEP), Protecting the Environment During Armed Conflict, 2009, p. 9.

3 Hulme, Karen, “Environmental Protection in Armed Conflict”, in Fitzmaurice, Malgosia, Ong, David M. and Merkouris, Panos (eds), Research Handbook on International Environmental Law, Edward Elgar, Cheltenham, 2010, p. 586Google Scholar.

4 International Committee of the Red Cross (ICRC), ICRC Engagement with Non-State Armed Groups: Why, How, for What Purpose, and Other Salient Issues, position paper, Geneva, 2021, p. 3.

5 ICRC, How Is the Term ‘Armed Conflict’ Defined in International Humanitarian Law?, opinion paper, Geneva, 2008, p. 5; International Criminal Tribunal for the former Yugoslavia (ICTY), Prosecutor v. Duško Tadić, Case No. IT-94-1, Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction (Appeals Chamber), 2 October 1995, para. 70.

6 Armed groups that are parties to a NIAC are called non-State armed groups (NSAGs). See ICRC, above note 4, pp. 2–3.

7 ICRC, Strengthening Legal Protection for Victims of Armed Conflicts, report submitted to the 31st International Conference of the Red Cross and Red Crescent, 2011, p. 14.

8 Ibid.

9 Marja Lehto, Report of the Special Rapporteur on the Protection of the Environment in Relation to Armed Conflicts, UN Doc. A/CN.4/728, 27 March 2019, pp. 23–28; Kubo Mačák, “Strengthening the Rule of Law in Time of War: An IHL Perspective on the Present and Future of the Articles on State Responsibility”, EJIL: Talk!, 6 August 2021, available at: www.ejiltalk.org/strengthening-the-rule-of-law-in-time-of-war-an-ihl-perspective-on-the-present-and-future-of-the-articles-on-state-responsibility/ (all internet references were accessed in October 2021).

10 International Law Commission (ILC), Draft Articles on the Responsibility of States for Internationally Wrongful Acts, 2001, Art. 10.

11 M. Lehto, above note 9, p. 9.

12 UNEP, above note 2, p. 10.

13 Ibid., p. 8.

14 Gus Waschefort, “Wild Fauna and Flora Protection”, in Robin Geiß and Nils Melzer (eds), The Oxford Handbook of the International Law of Global Security, Oxford University Press, Oxford, 2021, p. 618.

In 2013, the UN Secretary-General held that the “illegal ivory trade may currently constitute an important source of funding for armed groups, including [the] LRA”. See UN Security Council, Report of the Secretary-General on the Activities of the United Nations Regional Office for Central Africa and on the Lord's Resistance Army-Affected Areas, UN Doc. S/2013/297, 20 May 2013, para. 9.

15 Sivakumaran, Sandesh, The Law of Non-International Armed Conflict, Oxford University Press, Oxford, 2012, p. 528Google Scholar.

16 ICRC, “Natural Environment: Neglected Victim of Armed Conflict”, 5 June 2019, available at: www.icrc.org/en/document/natural-environment-neglected-victim-armed-conflict.

17 See, for example, Joint Urban Operations, US Joint Publication 3-06, 20 November 2013, p. III-11, section m(1)(b), cited in Gillard, Emanuela-Chiara, Proportionality in the Conduct of Hostilities: The Incidental Harm Side of the Assessment, Chatham House, 2018, p. 48Google Scholar. “In urban concentrations of people and infrastructure, the potential for serious environmental consequences is typically greater than in less populated areas.”

18 Conflict and Environment Observatory (CEOBS), “How Does War Damage the Environment?”, 4 June 2020, available at: https://ceobs.org/how-does-war-damage-the-environment/.

19 Dathan, Jennifer, Explosive Violence Monitor 2019, Action on Armed Violence, London, 2020, p. 16Google Scholar.

20 Ibid.

21 Ibid., p. 28. On the use of explosive weapons by NSAGs, see also Brehm, Maya, “The Use of Explosive Weapons in Populated Areas in 2012”, in Casey-Maslen, Stuart (ed.), The War Report: 2012, Oxford University Press, Oxford, 2013Google Scholar; United Nations Institute for Disarmament Research, Addressing Improvised Explosive Devices: Options and Opportunities to Better Utilize UN Processes and Actors, Geneva, 2015.

22 Anki Sjöberg, “The Involvement of Armed Non-State Actors in the Landmine Problem: A Call for Action”, executive summary, Geneva Call, Geneva, 2004, p. 13.

23 International Campaign to Ban Landmines – Cluster Munition Coalition (ICBL-CMC), Landmine Monitor 2019, 2019, p. 11.

24 Claudio Torres-Nachón, “Environmental Aspects of the International Crisis of Antipersonnel Landmines and the Implementation of the 1997 Mine Ban Treaty”, in ICBL-CMC, Landmine Monitor 2000, 2000, available at: www.hrw.org/reports/2000/landmines/LMWeb-54.htm#TopOfPage.

25 See Carmen M. Cusack, Animals and Criminal Justice, Routledge, New York, 2017, p. 209; “Police: Bombs Tied to Donkeys Kill 2, Wound 6”, NBC News, 12 September 2009, available at: www.nbcnews.com/id/wbna32809264.

26 See Zwijnenburg, Wim and Postma, Foeke, Living Under a Black Sky: Conflict Pollution and Environmental Health Concerns in Iraq, PAX, Utrecht, 2017Google Scholar.

27 “IS Oil Wells Set on Fire as Iraqi Troops Approach Mosul”, BBC News, 6 November 2016, available at: www.bbc.com/news/av/world-middle-east-37891389.

28 Nett, Katharina and Rüttinger, Lukas, Insurgency, Terrorism and Organised Crime in a Warming Climate: Analysing the Links between Climate Change and Non-State Armed Groups, Climate Diplomacy, Berlin, 2016, p. 12Google Scholar.

29 Ibid., p. 18.

30 ICRC, Handbook on International Rules Governing Military Operations, Geneva, 2013, pp. 30–31.

31 On the importance of NSAG doctrine, see, for example, Anne Quintin and Marie-Louise Tougas, “Generating Respect for the Law by Non-State Armed Groups: The ICRC's Role and Activities”, in Ezequiel Heffes, Marcos D. Kotlik and Manuel J. Ventura (eds), International Humanitarian Law and Non-State Actors, Asser Press, The Hague, 2020, pp. 359–366; Jonathan Somer, “Environmental Protection and Non-State Armed Groups: Setting a Place at the Table for the Elephant in the Room”, CEOBS, 4 December 2015, available at: https://ceobs.org/environmental-protection-and-non-state-armed-groups-setting-a-place-at-the-table-for-the-elephant-in-the-room/; ICRC, “A Collection of Codes of Conduct Issued by Armed Groups”, International Review of the Red Cross, Vol. 93, No. 882, 2011, pp. 483–486.

32 Pascal Bongard, From Words to Deeds: A Research Study of Armed Non-State Actors’ Practice and Interpretation of International Humanitarian and Human Rights Norms: The National Movement for the Liberation of Azawad, Mali, Geneva Academy of International Humanitarian Law and Human Rights (Geneva Academy), Geneva, 2021, pp. 14–15.

33 As cited in J. Somer, above note 31.

34 Ibid.

35 Ibid.

36 Ibid. (emphasis added).

37 Ibid.

38 Ibid.

39 Ibid.

40 “Wanted Rebels Pledge to Save Rhinos”, Al Jazeera, 21 August 2006, available at: www.aljazeera.com/news/2006/8/21/wanted-rebels-pledge-to-save-rhinos; S. Sivakumaran, above note 15, p. 528.

41 Ibid.

42 J. Somer, above note 31; see also S. Sivakumaran, above note 15, p. 528.

43 Olivier Bangerter, Internal Control: Codes of Conduct within Insurgent Armed Groups, Small Arms Survey, Graduate Institute of International and Development Studies, Geneva, 2012, p. 28. These measures are addressed in more detail below.

44 Ibid., p. 36.

45 Ibid.

46 Ibid.

47 Ibid., pp. 36–37.

48 Ibid., p. 37.

49 G. Waschefort, above note 14, p. 617.

50 Ibid., p. 618.

51 ICRC Guidelines, above note 1.

52 Vanessa Murphy and Helen Obregón Gieseken, “Fighting Without a Planet B: How IHL Protects the Natural Environment in Armed Conflict”, Humanitarian Law and Policy Blog, 25 May 2021, available at: https://blogs.icrc.org/law-and-policy/2021/05/25/fighting-without-planet-b/.

53 ICRC, Commentary on the Third Geneva Convention: Convention (III) relative to the Treatment of Prisoners of War, 2nd ed., Geneva, 2020 (ICRC Commentary on GC III), para. 551.

54 ICRC, above note 31, p. 484.

55 Henckaerts, Jean-Marie and Doswald-Beck, Louise (eds), Customary International Humanitarian Law, Vol. 1: Rules, Cambridge University Press, Cambridge, 2005CrossRefGoogle Scholar (ICRC Customary Law Study), Rule 43, available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul. On the civilian character of the natural environment, see ICRC Guidelines, above note 1, pp. 19–21, paras 18–21.

56 ICRC Customary Law Study, above note 55, Rules 11, 43(A).

57 Ibid., Rule 43(C).

58 ICRC Guidelines, above note 1, p. 56, para. 117.

59 Ahmed Al-Dawoody and Sarah Gale, “Protection of the Environment and Non-State Armed Groups: IHL and Islamic Law Perspectives”, Armed Groups and International Law, 6 November 2020, available at: https://armedgroups-internationallaw.org/2020/11/06/protection-of-the-environment-and-non-state-armed-groups-ihl-and-islamic-law-perspectives/.

60 ICTY, 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. 22.

61 UNEP, above note 2, p. 13.

62 ICRC Guidelines, above note 1, p. 57, para. 121.

63 Sassòli, Marco, International Humanitarian Law: Rules, Controversies, and Solutions to Problems Arising in Warfare, Edward Elgar, Cheltenham, 2019, p. 362CrossRefGoogle Scholar.

64 Pascal Bongard, cited in Kira Walker, “Can Militant Groups Be Environmentalists?”, World Politics Review, 29 April 2020, available at: www.worldpoliticsreview.com/articles/28718/the-case-for-engaging-with-militant-groups-to-protect-the-environment.

65 ICRC Customary Law Study, above note 55, Rule 15; ICRC Guidelines, above note 1, p. 58, para. 126.

66 ICRC Customary Law Study, above note 55, Rules 15, 17.

67 Ibid., Rules 16, 18.

68 Ibid., Rule 19.

69 Ibid., Rule 22.

70 Call, Geneva, In Their Words: Six Armed Non-State Actors Share Their Policies and Practice with Regards to Protecting Civilians from Explosive Weapons, Geneva, 2017, p. 5Google Scholar.

71 A. Al-Dawoody and S. Gale, above note 59.

72 On the contextual factors influencing the application of the principle of proportionality, see ICRC, The Principle of Proportionality in the Rules Governing the Conduct of Hostilities under International Humanitarian Law, report of the International Expert Meeting, Geneva, 2016, pp. 60–62.

73 ICRC Guidelines, above note 1, p. 59, para. 129.

74 Ibid., paras 129–130.

75 ICRC Customary Law Study, above note 55, Rule 53; 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) (AP II), Art. 14.

76 AP II, Art. 14; ICRC Customary Law Study, above note 55, Rule 54.

77 ICRC Guidelines, above note 1, p. 18, para. 16.

78 AP II, Art. 15; ICRC Customary Law Study, above note 55, Rule 42.

79 ICRC Customary Law Study, above note 55, Rule 148.

80 Ibid., Rule 71.

81 Ibid., Rule 72.

82 Ibid., Rule 73.

83 Ibid., Rule 74.

84 Ibid., Rule 76.

85 Ibid., Rules 81, 83.

86 Ibid., Rules 84–85.

87 ICRC Guidelines, above note 1, Rule 23.

88 Ibid., Rule 24

89 Ibid., Rule 25.

90 ICRC, International Humanitarian Law and the Challenges of Contemporary Armed Conflicts, Geneva, 2019, pp. 20–21.

91 Ibid.

92 Article 3 common to the four Geneva Conventions; AP II, Art. 4.

93 AP II, Art. 17; ICRC Customary Law Study, above note 55, Rule 129(B).

94 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict, 249 UNTS 215, 14 May 1954 (entered into force 7 August 1956), Art. 1; AP II, Art. 16; ICRC Customary Law Study, above note 55, Rule 38; ICRC Guidelines, above note 1, Rule 12.

95 ICRC Customary Law Study, above note 55, Rules 36–37.

96 Ibid., Rules 43(B), 50.

97 Declaration Renouncing the Use, in Time of War, of Explosive Projectiles Under 400 Grammes Weight, Saint Petersburg, 29 November/11 December 1868.

98 Johansen, Sigrid Redse, The Military Commander's Necessity, Cambridge University Press, Cambridge, 2019, p. 27CrossRefGoogle Scholar.

99 Jong, Daniëlla Dam-de, International Law and Governance of Natural Resources in Conflict and Post-Conflict Situations, Cambridge University Press, Cambridge, 2015, p. 226CrossRefGoogle Scholar.

100 S. R. Johansen, above note 98, p. 348.

101 Ibid., p. 346.

102 US Department of Defense, Law of War Manual, 2016, para. 5.17.2.2.

103 ICRC Guidelines, above note 1, p. 75, para. 180.

104 ICRC Customary Law Study, above note 55, Rule 52.

105 International Criminal Court, Elements of Crimes, Art. 8(2)(e)(v).

106 ICRC Guidelines, above note 1, p. 76, para. 183.

107 M. Sassòli, above note 63, p. 294.

108 Daniëlla Dam-de Jong, “Between Paradox and Panacea: Legalizing Exploitation of Natural Resources by Armed Groups in the Fight against Conflict Resources”, Armed Groups and International Law, 18 June 2019, available at: https://armedgroups-internationallaw.org/2019/06/18/between-paradox-and-panacea-legalizing-exploitation-of-natural-resources-by-armed-groups-in-the-fight-against-conflict-resources/.

109 Hague Convention (IV) respecting the Laws and Customs of War on Land and Its Annex: Regulations Concerning the Laws and Customs of War on Land, 205 CTS 227, 18 October 1907 (entered into force 26 January 1910), Art. 55.

110 M. Sassòli, above note 63, p. 332.

111 Ibid.

112 D. Dam-de Jong, above note 108.

113 Dinstein, Yoram, The International Law of Belligerent Occupation, 2nd ed., Cambridge University Press, Cambridge, 2019, pp. 37–38CrossRefGoogle Scholar.

114 ICRC Customary Law Study, above note 55, Rule 44.

115 Ibid., Rule 45.

116 Ibid.

117 Ibid., commentary on Rule 45; S. Sivakumaran, above note 15, p. 527.

118 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), Arts 1(4), 96(3).

119 ICRC Guidelines, above note 1, Recommendation 18.

120 Ibid., Recommendation 17, pp. 82–83; ILC, Draft Principles on the Protection of the Environment in Relation to Armed Conflicts, UN Doc. A/CN.4/L.937, 6 June 2019, Principle 4.

121 See S. Sivakumaran, above note 15, pp. 83–86.

122 ICRC Commentary on GC III, above note 53, para. 551.

123 See, for example, UN Office of the High Commissioner for Human Rights (UN Human Rights), “Joint Statement by Independent United Nations Human Rights Experts on Human Rights Responsibilities of Armed Non-State Actors”, 25 February 2021, Geneva, available at: www.ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=26797&LangID=E; Bellal, Annyssa, Human Rights Obligations of Armed Non-State Actors: An Exploration of the Practice of the UN Human Rights Council, Geneva Academy, Geneva, 2016Google Scholar.

124 ICRC Commentary on GC III, above note 53, para. 551.

125 Kleffner, Jann K., “Human Rights in Armed Conflict”, in Fleck, Dieter (ed.), The Handbook of International Humanitarian Law, 4th ed., Oxford University Press, Oxford, 2021, p. 451Google Scholar.

126 International Covenant on Economic, Social and Cultural Rights, 993 UNTS 3, 16 December 1966 (entered into force 3 January 1976) (ICESCR), Art. 12.

127 Common Article 3(2); AP II, Arts 7–8; ICRC Customary Law Study, above note 55, Rules 109–111.

128 Fortin, Katharine, “The Application of Human Rights Law to Everyday Civilian Life under Rebel Control”, Netherlands International Law Review, Vol. 63, No. 2, 2016, p. 171CrossRefGoogle Scholar.

129 ICRC, above note 4, p. 2.

130 UNEP, above note 2, pp. 48–50; ICRC Guidelines, above note 1, pp. 26–27.

131 HRC, General Comment No. 36, “Article 6: Right to Life”, UN Doc. CCPR/C/GC/36, 3 September 2019, para. 62.

132 HRC, Portillo Cáceres v. Paraguay, Communication No. 2751/2016, UN Doc. CCPR/C/126/D/2751/2016, 20 September 2019.

133 John H. Knox, Report of the Special Rapporteur on the Issue of Human Rights Obligations relating to the Enjoyment of a Safe, Clean, Healthy and Sustainable Environment, UN Doc. A/HRC/37/59, 24 January 2018.

134 Ibid., “Framework Principles on Human Rights and the Environment”.

135 Ibid., p. 3.

136 Ibid., Framework Principle 1.

137 Ibid., commentary on Framework Principles 1 and 2, pp. 7–8.

138 Rodenhäuser, Tilman, Organizing Rebellion: Non-State Armed Groups under International Humanitarian Law, Human Rights Law, and International Criminal Law, Oxford University Press, Oxford, 2018, pp. 146–209CrossRefGoogle Scholar; A. Bellal, above note 123; Geneva Call, Positive Obligations of Armed non-State Actors: Legal and Policy Issues, Geneva, 2015.

139 This approach has notably been adopted by Milanovic as regards the extraterritorial application of human rights treaties. Milanovic, Marko, Extraterritorial Application of Human Rights Treaties: Law, Principles, and Policy, Oxford University Press, Oxford, 2011, pp. 209–219CrossRefGoogle Scholar. The ICRC has also made a distinction between negative and positive obligations for the application of the law of occupation. ICRC Commentary on GC III, above note 53, para. 356.

140 UN Human Rights, “International Human Rights Law”, available at: www.ohchr.org/en/professionalinterest/pages/internationallaw.aspx.

141 M. Milanovic, above note 139, p. 210.

142 UN Human Rights, above note 140.

143 Ibid.

144 M. Milanovic, above note 139, p. 210.

145 ICRC Commentary on GC III, above note 53, para. 551.

146 Rodenhäuser suggests three categories of NSAGs: “groups exercising quasi-governmental authority in defined territory; groups exercising de facto control over territory and population; [and] groups not exercising control over territory and population”. T. Rodenhäuser, above note 138, p. 148. See also Geneva Call, above note 138.

147 See T. Rodenhäuser, above note 138, p. 178. In addition to NSAGs exercising government-like functions, some have even argued that “armed non-State actors exercising … de facto control over territory and population must respect and protect the human rights of individuals and groups”. See UN Human Rights, above note 123.

148 Convention on the Rights of the Child, 1577 UNTS 3, 20 November 1989 (entered into force 2 September 1990), Art. 24(2)(c).

149 Committee on Economic, Social and Cultural Rights (CESCR), General Comment No. 14, “Article 12: Right to the Highest Attainable Standard of Health”, UN Doc. E/C.12/2000/4, 11 August 2000, para. 27.

150 J. H. Knox, above note 133, Framework Principle 8.

151 Ibid., Framework Principle 10.

152 ICESCR, Art. 2(1).

153 International Covenant on Civil and Political Rights (ICCPR), 999 UNTS 171, 16 December 1966 (entered into force 23 March 1976), Art. 4(3).

154 J. H. Knox, above note 133, commentary on Framework Principle 1, p. 6.

155 CESCR, above note 149, para. 34.

156 As discussed above. The Treaty on the Prohibition of Nuclear Weapons, 7 July 2017 (entered into force 22 January 2021), prohibits the use of nuclear weapons by States parties to the Treaty.

157 Common Article 3(1)(a).

158 Although it initially developed as an anthropocentric body of law. See, for example, the 1900 Convention Designed to Ensure the Conservation of Various Species of Wild Animals in Africa which are Useful to Man or Inoffensive, or the 1902 Convention for the Protection of Birds Useful to Agriculture.

159 UNEP, above note 2, p. 52; ICRC Guidelines, above note 1, pp. 23–26.

160 UN General Assembly, World Charter for Nature, UN Doc. A/RES/37/7, 28 October 1982, para. 21(c).

161 Regarding IHRL, see T. Rodenhäuser, above note 138, p. 171. Regarding IHL, see Kleffner, Jann K., “The Applicability of International Humanitarian Law to Organized Armed Groups”, International Review of the Red Cross, Vol. 93, No. 882, 2011, pp. 445–449CrossRefGoogle Scholar.

162 J. K. Kleffner, above note 161, pp. 451–454; T. Rodenhäuser, above note 138, pp. 172–176.

163 T. Rodenhäuser, above note 138, pp. 176–177; J. K. Kleffner, above note 161, pp. 454–456.

164 Kravchenko, Svitlana, Chowdhury, Tareq M. R. and Bhuiyan, Jahid Hossain, “Principles of International Environmental Law”, in Alam, Shawkat, Bhuiyan, Jahid Hossain, Chowdhury, Tareq M. R. and Techera, Erika J. (eds), Routledge Handbook of International Environmental Law, Routledge, London, 2014, p. 57Google Scholar.

165 Ibid., p. 54.

166 Convention for the Protection of the World Cultural and Natural Heritage, 1037 UNTS 151, 16 November 1972 (entered into force 17 December 1975), Art. 5(b).

167 International Court of Justice (ICJ), Pulp Mills on the River Uruguay (Argentina v. Uruguay), Judgment, ICJ Reports 2010, para. 101.

168 According to Michael Bothe, the principle of precaution is a “fundamental rule of modern customary environmental law”. Michael Bothe, “Protection of the Environment in Relation to Armed Conflicts”, in Dieter Fleck (ed.), above note 125, p. 343. However, the customary nature of the precautionary principle remains contested. See Meinhard Schröder, “Precautionary Approach/Principle”, in Max Planck Encyclopedia of Public International Law, 2014, paras 16–21.

169 ILC, Draft Articles on Prevention of Transboundary Harm from Hazardous Activities, 2001, Art. 3; Permanent Court of Arbitration, Arbitration regarding the Iron Rhine (“Ijzeren Rijn”) Railway (Belgium v. The Netherlands), 2005, paras 59, 222; ICJ, Pulp Mills, above note 167, para. 101.

170 Rio Declaration on Environment and Development, UN Doc. A/CONF.151/26, 12 August 1992 (Rio Declaration), Principle 17.

171 Unofficial Translation of CNF–Government Agreements at Union-Level Peace Talks, 9 December 2012 (CNF Agreements), para. 6, available at: www.peaceagreements.org/viewmasterdocument/1321.

172 Rio Declaration, above note 170, Principle 15. The precautionary principle applies in armed conflict and entails that “the lack of scientific certainty may not be invoked to justify not taking preventive measures to protect the environment during an attack”: ICRC Customary Law Study, above note 55, Rule 44. See also ICRC Guidelines, above note 1, p. 58, para. 124.

173 Rio Declaration, above note 170, Principle 15.

174 Convention on International Trade in Endangered Species of Wild Fauna and Flora, 993 UNTS 243, 3 March 1973 (entered into force 1 July 1975).

175 Trail Smelter Case (United States v. Canada), 16 April 1938 and 11 March 1941, Reports of International Arbitral Awards, Vol. 3, 2006, p. 1965. The “no harm” principle was subsequently crystallized in the Declaration of the United Nations Conference on the Human Environment, UN Doc. A/CONF.48/14/Rev.1, 16 June 1972, Principle 21, and the Rio Declaration, above note 170, Principle 2.

176 In situations of international armed conflict, some authors have argued that “[t]he Trail Smelter principle may afford protection to non-belligerent, neutral territories by establishing state responsibility for environmental damage caused outside the state where the acts or events entailing such damage occur”. Bothe, Michael, Bruch, Carl, Diamond, Jordan and Jensen, David, “International Law Protecting the Environment during Armed Conflict: Gaps and Opportunities”, International Review of the Red Cross, Vol. 92, No. 879, 2010, p. 585CrossRefGoogle Scholar.

177 ILC, Report of the International Law Commission, Seventy-First Session, UN Doc. A/74/10, 2019, pp. 276–278.

178 Ibid. For a similar view, see D. Dam-de Jong, above note 108.

179 CNF Agreements, above note 171.

180 Bangerter, Olivier, “Reasons Why Armed Groups Choose to Respect International Humanitarian Law or Not”, International Review of the Red Cross, Vol. 93, No. 882, 2011, p. 357CrossRefGoogle Scholar.

181 See, for example, ICRC, The Roots of Restraint in War, Geneva, 2018; Sivakumaran, Sandesh, “Implementing Humanitarian Norms through Non-State Armed Groups”, in Krieger, Heike (ed.), Inducing Compliance with International Humanitarian Law, Cambridge University Press, Cambridge, 2015Google Scholar; Bellal, Annyssa and Casey-Maslen, Stuart, Rules of Engagement: Protecting Civilians through Dialogue with Armed Non-State Actors, Geneva Academy, Geneva, 2011Google Scholar; Sassòli, Marco, “Taking Armed Groups Seriously: Ways to Improve their Compliance with International Humanitarian Law”, Journal of International Humanitarian Legal Studies, Vol. 1, No. 1, 2010CrossRefGoogle Scholar; ICRC, Increasing Respect for International Humanitarian Law in Non-International Armed Conflicts, Geneva, 2008.

182 UN Secretary-General, Protection of Civilians in Armed Conflict: Report of the Secretary-General, UN Doc. S/2018/462, 14 May 2018, para. 62.

183 A. Bellal and S. Casey-Maslen, above note 181, p. 6.

184 M. Sassòli, above note 181, p. 29. See also S. Sivakumaran, above note 181, pp. 130–131.

185 Where they can be achieved, special agreements constitute valuable means of commitment, as explained in Heffes, Ezequiel and Kotlik, Marcos D., “Special Agreements as a Means of Enhancing Compliance with IHL in Non-International Armed Conflicts: An Inquiry into the Governing Legal Regime”, International Review of the Red Cross, Vol. 96, No. 895–896, 2015, pp. 1198–1200Google Scholar.

186 Nils Melzer, International Humanitarian Law: A Comprehensive Introduction, ICRC, Geneva, 2016, p. 307.

187 ICRC, Increasing Respect, above note 181, p. 19.

188 According to the ICRC, “[i]f an armed group has made a unilateral declaration, the development of a code of conduct that includes IHL can be suggested as a logical ‘next step’.” See ibid., p. 22.

189 See S. Sivakumaran, above note 181, pp. 133–137; M. Sassòli, above note 181, p. 25.

190 For more details on dissemination, training and sanctions measures, see O. Bangerter, above note 43, pp. 28–32.

191 Engagement by other actors is also important. The World Wide Fund for Nature and UNESCO have notably attempted to protect the environment in certain contexts. See K. Walker, above note 64.

192 ICRC, Increasing Respect, above note 181, pp. 30–31.

193 This consideration impacts respect for IHL rules, according to O. Bangerter, above note 180, p. 384.

194 Ibid.

195 See ICRC, “Sudan/South Sudan, Commitment of Non-State Armed Groups against Anti-Personnel Landmines and South Sudan's Ratification of the Ottawa Convention”, IHL in Action: Respect for the Law on the Battlefield, available at: https://ihl-in-action.icrc.org/case-study/sudansouth-sudan-commitment-non-state-armed-groups-against-anti-personnel-landmines-and.

196 ICRC, above note 4, p. 9.

197 Ahmed Al-Dawoody and Sarah Gale, “Protecting the Environment during Armed Conflict: IHL and Islamic Law”, Humanitarian Law and Policy Blog, 3 June 2021, available at: https://blogs.icrc.org/law-and-policy/2021/06/03/protecting-environment-armed-conflict-ihl-islamic-law/.

198 ICRC, Toolbox: Safeguarding the Provision of Health Care, Geneva, February 2016, p. 21, available at: https://shop.icrc.org/toolbox-safeguarding-the-provision-of-health-care-operational-practices-and-relevant-internationalhumanitarian-law-concerning-armed-groups-pdf-en.

199 See ibid.

200 See ICRC, above note 4.

201 Ibid., p. 2.

202 ICRC Guidelines, above note 1, Recommendation 17, pp. 82–83.

203 For further information, see the Geneva Call website, available at: www.genevacall.org/.

204 Inspired by the ICRC model unilateral declaration related to the protection of health care, in ICRC, above note 198, and Geneva Call's Deeds of Commitment.