The ILC Draft Principles on Protection of the Environment in Armed Conflict

by | Aug 4, 2022

ILC protection of environment


After almost a decade working on the topic “Protection of the environment in relation to armed conflicts” (PERAC), the UN International Law Commission (ILC) adopted on second reading 27 draft principles and a preamble during the first part of its 73rd session. This process was skillfully led throughout by the two Special Rapporteurs on the topic, the former one, Ambassador Marie Jacobsson, and the current, Ambassador Marja Lehto.

Following the adoption of the draft principles on first reading in 2019, the ILC invited States, international organizations, and others to submit their written observations. It is quite remarkable that more than twenty States, as well as several international and non-governmental organizations heeded this call. The ILC is expected to adopt the associated commentaries and then submit the final output of its work to the UN General Assembly for consideration.

The comprehensive set of the PERAC draft principles could be situated alongside a host of initiatives, undertaken by various international actors, such as the 2020 International Committee of the Red Cross (ICRC) Guidelines on the Protection of the Natural Environment in Armed Conflict, the adoption of two relevant resolutions by the UN Environment Assembly in 2016 and 2017 (here and here), the 2019 Geneva List of Principles on the Protection of Water Infrastructure, and the victim assistance principles for those affected by toxic remnants of war. These initiatives not only showcase the increased awareness of the international community for PERAC-related issues. They also strengthen and complement the existing normative terrain of PERAC.

Against this background, this post addresses cross-cutting themes of the ILC’s PERAC draft principles. Subsequently, it discusses selected issues of the ILC’s endeavor, with special emphasis on the in bello period.

Cross-Cutting Themes and the ILC’s Comprehensive Approach

It should be noted at the outset that the purpose of the ILC’s work under consideration is to “enhanc[e] the protection of the environment in relation to armed conflicts, including through measures to prevent, mitigate and remediate harm to the environment” (draft principle 2). The ILC’s draft principles are unique in that they espouse a comprehensive approach to PERAC.

Temporal Scope

The ILC PERAC draft principles cover the entire conflict cycle by following a temporal approach, as provided for in draft principle 1. Their second part encapsulates principles of general application, that is, principles that apply to more than one conflict phase (before, during or after, including in situations of occupation). Their third part covers principles applicable during armed conflict. Their fourth part deals with environmental protection in situations of occupation. And the last part addresses the period after an armed conflict.

Personal Scope

Turning to the personal scope of their application, it becomes evident from a plain reading that the ILC’s PERAC draft principles are primarily addressed to States. Nevertheless, they cast their net wider by bringing within their ambit other actors in international affairs, such as international organizations (see principles 6-8, 23-25), and other relevant actors (principles 8 and 25), such as non-state actors. Furthermore, draft principles 10 and 11 aspire to regulate corporate environmental conduct in areas affected by armed conflict. Given that the ILC chose to adopt a non-differentiation approach between international armed conflicts (IACs) and non-international armed conflicts (NIACs), the environment-related conduct of non-state armed groups also comes within the purview of the PERAC draft principles, especially with respect to the in bello phase (Part Three).

No Differentiation of Conflict Type

The latter feature deserves closer scrutiny taking into account, for instance, that the environment-specific treaty provisions under the law of armed conflict (LOAC), namely articles 35(3) and 55 of Additional Protocol I apply, in principle, to IACs. In this respect, the ILC opted to draw the necessary distinctions between the law applicable to IACs and to NIACs not in the text of the draft principles per se, but rather in the commentaries, which should be read together with the draft principles.

Insights from International Law

Another element of the draft principles that attests to their comprehensive nature is the fact that their text draws insights from various fields of international law. By means of illustration, draft principle 5 draws its wording from the UN Declaration on the Rights of Indigenous Peoples; draft principle 9 may be seen as an adjustment of the law of State responsibility to the peculiarities of environmental harm in relation to armed conflict; draft principle 21 transposes the international environmental law (IEL) no-harm principle to situations of occupation; and international human rights law has inspired the wording of preambular paragraph 4 and draft principle 19(2), which applies in situations of occupation.

In sum, the ILC has proficiently articulated an inclusive set of draft principles in terms of temporal and personal scope, integrating rules and principles stemming from various areas of international law, while also not differentiating between IACs and NIACs.

Selected Issues relating to LOAC

“Natural environment” versus “Environment”

The current section deals with selected issues pertaining to the draft principles applicable during armed conflict (Part Three) and those applicable to situations of occupation (Part Four). Before moving to a principle-by-principle analysis, it is important to highlight that the ILC agreed to drop the qualifier “natural” before the term “environment,” pursuant to its comprehensive approach outlined above and in line with the title of the topic under consideration. While this deletion was already agreed upon for the other conflict phases, it remained an open-ended issue for the in bello phase as “natural environment” is the term used by the environment-specific provisions of Additional Protocol I (articles 35(3) and 55), the ICC Statute, and the ICRC’s work on PERAC, namely rules 43-45 of the ICRC Study on Customary IHL and its 2020 Guidelines on the Protection of the Natural Environment in Armed Conflict.

As the Chairman of the ILC Drafting Committee clarifies, the deletion of the epithet “natural” has been a longstanding issue throughout the ILC’s work on the topic. Both the Plenary and the Drafting Committee considered the issue. The underlying concern was, on the one hand, to ensure the consistent use of the same term “environment” throughout the text of the draft principles, and, on the other hand, to justify the departure from the established terminology used in relevant LOAC treaties. In the end, the Drafting Committee agreed on its deletion “on the understanding that, by deleting this word, the Commission did not intend to alter the scope of the existing conventional and customary international humanitarian law, nor was the Commission attempting to expand the scope of what is meant by ‘natural environment’ in international humanitarian law” (pp. 17-18). It was further decided that this understanding will be reflected in the associated commentaries.

An Environmental Martens Clause

Draft principle 12 expands the protective operation of the famous Martens clause to the protection of the environment. An environmental Martens clause could, at first sight, be viewed as conflating the dividing lines between the concepts of “humanity” relating to persons and the “environment” relating to natural surroundings. Nevertheless, as Germany insightfully noted in its written observations, the principle of humanity could be interpreted as encompassing the anthropocentric prong of environmental protection, with “the dictates of public conscience” serving a complementary and mutually enforcing role by reflecting the eco-centric approach (para. 6).

In bello General Protection of the Environment

Draft principle 13 details the general protection of the environment during armed conflict. In fact, this principle, and specifically its first and third paragraphs (“The environment shall be respected and protected in accordance with applicable international law and, in particular, the law of armed conflict”; “No part of the environment may be attacked, unless it has become a military objective”) reaffirm that the environment and parts thereof qualify as civilian objects for the purposes of LOAC. It bears noting that the 2020 ICRC Guidelines follow the same path (pp. 19-21). Accordingly, the environment benefits from the general protection afforded by LOAC to civilian objects. This finding is further strengthened by draft principle 14 (“The law of armed conflict, including the principles and rules on distinction, proportionality and precautions shall be applied to the environment, with a view to its protection”), to which I will return in a moment.

Environment-Specific Provisions of Additional Protocol I

Draft principle 13(2) warrants detailed treatment, as the ILC substantially altered it during the current session. The text adopted on first reading in 2019 reflected the obligation to take care to protect the environment against widespread, long-term, and severe damage. In other words, it was inspired from the text of the first sentence of article 55(1) of Additional Protocol I. Its current and final wording is as follows: “Subject to applicable international law: (a) care shall be taken to protect the environment against widespread, long-term and severe damage; (b) the use of methods and means of warfare that are intended, or may be expected, to cause widespread, long-term and severe damage to the environment is prohibited.”

The ILC later added a new subparagraph under (b), which was modelled around the eco-centric provision of article 35(3) of Additional Protocol I. This is a welcome addition, in light of the written comments asking for it and as the current Special Rapporteur explains in her third report, because such a provision sets “an absolute limit to the environmental harm caused in the conduct of hostilities”(para 143).

This addition, nevertheless, begs the question of the legal status of the norm reflected in draft principle 13(2). To put it simply, the first question would be whether articles 35(3) and the first sentence of article 55(1) of Additional Protocol I have crystalized into customary international law. Assuming that they have, more questions arise which further complicate the issue. For example, do they also apply to the use of nuclear weapons in light of relevant States’ views and declarations? Would they equally apply to NIACs, taking into account that Additional Protocol II contains no environment-specific provision? It comes as no surprise that this is an enduring, thorny question under the law of PERAC. The same set of troubling questions apply to draft principle 15 on reprisals, which reproduces article 55(2) of Additional Protocol I, except for the word “natural” before the “environment”.

Regarding draft principle 13(2), the ILC included a chapeau provision, pursuant to which the obligation applies “[s]ubject to applicable international law.” This chapeau enabled the ILC to incorporate the text of the respective environment-specific treaty provisions, sidestepping the difficult questions enumerated above. These questions will be treated in more detail in the ILC commentaries, but the chapeau appears to indicate that the ILC would not consider these provisions to reflect customary international law. The side-effect of this choice, intended or not, was that the obligation to take care is also subject to this chapeau, whereas no such caveat was applicable to it after its adoption on first reading in 2019.

From another perspective, this choice differs markedly from how the ILC treated the environment-specific reprisals provision of Additional Protocol I, where it chose to reproduce the text of article 55(2) in draft principle 15 word-by-word, omitting the word “natural” before “environment” (“Attacks against the environment by way of reprisals are prohibited”). This draft principle raises the same set of questions outlined above (legal status under customary international law; application to the use of nuclear weapons; legal status in the context of a NIAC). I have discussed these issues in more detail elsewhere, so here I focus exclusively on the ILC’s approach, especially as compared to its treatment of the other environment-specific provisions found in Additional Protocol I.

To be more specific, the ILC has not added any kind of chapeau or qualification to the text of the provision itself, even though the differing views on all three issues have been extensively dealt with in the commentaries. This noteworthy difference may have various, and not necessarily mutually exclusive explanations, such as that the prohibition on attacks against the environment by way of reprisals is better established in customary international law than the other provisions; that the reprisals draft principle was already agreed to in 2015, while the prohibition on the use of methods and means of warfare by reference to the prescribed cumulative threshold of environmental damage was only added in 2022. In any event, and speculations aside, the essence is that the ILC chose to include a qualifying phrase signaling its reservations in the text of draft principle 13(2), while the relevant qualifications with respect to draft principle 15 on reprisals will be found only in the commentaries.

Cardinal LOAC Principles and the Environment

Draft principle 14 uncontroversially provides that “[t]he law of armed conflict, including the principles and rules on distinction, proportionality and precautions shall be applied to the environment, with a view to its protection.” The ILC omitted the previous reference to “military necessity” from the text of draft principle 14, as “the notion of military necessity did not belong to the same order of generality as the other principles mentioned in the provision” (Statement of the Chairman of the Drafting Committee, p. 19). Articles of War has already addressed this issue.

It is noteworthy that the former draft principle 15 (“Environmental considerations shall be taken into account when applying the principle of proportionality and the rules on military necessity”), inspired by the dictum of the International Court of Justice in its Advisory Opinion on the Legality of the Threat or Use of Nuclear Weapons (para. 30), was eventually omitted from the second reading text as the ILC considered it redundant in light of its overlap with draft principle 14. Instead, a similarly worded paragraph found its way into the preamble (para. 5).


Draft principle 16 succinctly provides, “[p]illage of natural resources is prohibited.” Its text builds on well-established legal precedents and thus does not call for in-depth analysis.

Environmental Modification Techniques

Draft principle 17 (“In accordance with their international obligations, States shall not engage in military or any other hostile use of environmental modification techniques having widespread, long-lasting or severe effects as the means of destruction, damage or injury to any other State”), which draws its wording from the text of the ENMOD Convention follows the same route as draft principle 13(2) in that it is qualified through the use of the introductory phrase “in accordance with their international obligations.” In the same vein, the ILC opted to address the contentious issues of the customary status and the applicability of the relevant provision of the ENMOD Convention to NIACs in the commentaries.

Protected Zones and Integration of LOAC and International Environmental Law

Before moving to the occupation-related part of the ILC PERAC draft principles, it is important to dedicate a few lines to draft principle 18 on “Protected zones” (“An area of environmental importance, including where that area is of cultural importance, designated by agreement as a protected zone shall be protected against any attack, except insofar as it contains a military objective. Such protected zone shall benefit from any additional agreed protections”), which should be read together with draft principle 4 regarding their designation. On this issue, the ILC has made a commendable step by dropping the qualifier “major” before the phrase “environmental importance,” thus lowering the threshold and further broadening the range of such areas being capable of qualifying as “protected zones” for the purposes of this draft principle.

On the other hand, it is unclear to what type of protection zones that are designated by means other than an agreement between the belligerent parties are entitled, given that such a category of protected zones is envisaged by virtue of draft principle 4 (“States should designate, by agreement or otherwise, areas of environmental importance as protected zones in the event of an armed conflict, including where those areas are of cultural importance”).

However, this ambiguous point should not detract attention from the significance of draft principle 18. Through another lens, one cannot help noticing that such protected zones resemble the legal institution of “demilitarized zones” under LOAC. Equally, this type of area-based protection echoes the concept of in situ protection IEL. Drawing on familiar notions under both branches of international law, this draft principle evidently lies at the intersection of LOAC and IEL, showcasing the added value that the integration of different areas of international law can furnish to PERAC, in line with the ILC’s comprehensive approach outlined above.

Environmental Protection in Occupation

Last, a few final thoughts on Part Four pertaining to situations of occupation are worthwhile. The three occupation-related draft principles can be read as entailing an evolutionary interpretation of the law of occupation regarding environmental protection. These three draft principles foreground the integration of various fields of international law, such as LOAC, IEL, and international human rights law. It should be highlighted that the ILC decided during the second reading of the draft principles to add the qualifier “protected” before the terms “persons” (draft principle 19(2)) and “population” (draft principle 20) to harmonize their text with article 4 of Geneva Convention IV. This forms an important addition, because the first reading text of the respective draft principles could be used as a vehicle to extend such protections to settler populations (see the Joint Civil Society submission to the ILC).


The ILC PERAC draft principles comprise the culmination of several legal initiatives in this area of international law. The ILC’s final output would have benefited from an even stronger integration of the relevant branches of international law, especially of IEL. Additionally, the ICRC has recently published its 2020 Guidelines focusing on jus in bello, which purport to be “a restatement of the law as it stands in the eyes of the ICRC” (para. 12). This inevitably raises the question of the relationship between the two instruments, which, for the greatest part, could be seen as complementary. Be that as it may, the influence and respect the ILC enjoys within the international legal community, coupled with its very cautious stance on many controversial issues and its comprehensive approach could turn this instrument into the reference point on PERAC for years to come.

Following the adoption of the commentaries to the ILC PERAC draft principles, the next step is to refer this instrument to the UN General Assembly, which, in turn, should decide its fate. As the Ukraine-Russia conflict has made abundantly clear, it is high time that all parties concerned channel their efforts into the implementation of the applicable legal framework on PERAC, including of the ILC PERAC draft principles.

Author’s note: The author attended this year’s ILC proceedings in his capacity as an assistant to the Special Rapporteur Ambassador Marja Lehto. This activity was generously supported by the Kone Foundation. He was also the coordinator of the Joint Civil Society submission to the ILC.


Dr. Stavros-Evdokimos Pantazopoulos is a post-doctoral researcher with the Toxic Crimes Project of the Erik Castrén Institute at the University of Helsinki, and a researcher at the Asser Institute.


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