PERAC is a process to strengthen the legal framework protecting the environment from war. It formally began in 2013 when the topic was included in the UN’s International Law Commission’s programme of work. The UN Environment Programme had recommended that the Commission study the legal framework with a view to strengthening it in a report it published in 2009.

The PERAC principles are a set of 27 principles outlining how the environment should be protected before, during and after armed conflicts, and in situations of occupation. They vary in strength from non-binding guidance, to reflecting binding international law. The final draft version of the principles and their commentaries is available online.

We all understand that environmental protection is important because we all depend on a healthy environment. The environment doesn’t stop being important during wars, in some cases it can become even more important, for example when it helps sustain populations trying to cope with the impact of war. But war is also hugely destructive for the environment, just as it is for people. Often it is how wars are fought that damages the environment, at other times where. This is made worse when governments are distracted and unable to protect areas of environmental importance.

Legal regulation is one way to enhance the protection of the environment in conflicts. The PERAC process has tried to bring together knowledge of how the environment is affected by war, and strengthen or develop the law that was already there to make it better at protecting it.

The International Law Commission (ILC) is a body of experts responsible for helping develop and codify international law. It is composed of 34 individuals recognised for their expertise and qualifications in international law, who are elected by the UN General Assembly every five years.

When the International Law Commission (ILC) adopts a programme of work, it first appoints a special rapporteur for the topic. Because the process has lasted nearly a decade, PERAC has had two. The first was Amb Dr Marie Jacobsson of Sweden, the second, Amb Dr Marja Lehto of Finland. The special rapporteurs are responsible for framing the topic and the research, coming up with the outputs and for shepherding them through the ILC’s process. Because it’s international law, governments also need to have a say.

The PERAC process has seen repeated cycles whereby the special rapporteur writes a report on say, how the environment is affected during war, and what law is relevant, and then proposes a set of legal principles based on that law. This is presented to the ILC as a whole (plenary), and its members provide feedback. The special rapporteur has then sat down with a few ILC members (a drafting committee) to revise her principles based on this feedback. Next, the revised principles and their commentaries – which explain their justification, legal basis and how they should be understood – are presented to governments. This takes place at the UN General Assembly in its Sixth Committee, which deals with international law.

Once governments have a say, the special rapporteur goes back and revises the principles and commentaries. The PERAC process has generated six reports by its special rapporteurs and so repeated cycles of this iterative process. More than sixty countries chose to comment on the principles during the process, and there has also been a chance for international organisations and civil society to provide feedback. The ILC maintains an online record of all the documents created by the process.

There are a few things that are special about the PERAC principles. The first is that they were developed from a mixture of International Humanitarian Law (IHL), Environmental Law, Human Rights Law and other fields of law, as well as from the practice of states and non-state actors. The second thing is their temporal scope, they apply before, during and after armed conflicts, and in situations of occupation. The third thing is that they apply to both international armed conflicts, and non-international armed conflicts. The fourth thing is their scope, across 27 principles they cover a huge range of topics.

Before PERAC, the environment enjoyed limited protection under IHL, but that just applies during conflicts and occupations, and primarily in international armed conflicts. Now we have principles based on more bodies of law and other sources, across different parts of the cycle of armed conflicts and that address many more environmental problems.

While the International Law Commission can create processes that lead to the formation of new international conventions, it was felt early on in the PERAC process that this wouldn’t be practical or appropriate. Part of the problem was that a lot of states were expected to object to the process – this hasn’t proved as big a problem as first feared – but it also came down to the very broad scope of the principles, and their different sources of law, and practice, a lot of which wasn’t binding on states. Together this meant it was difficult to expect states to support a new international convention.

This is quite a complex question and depends on the principle in question. Sources of international law mostly include treaty law – the rules that states have signed up to, and customary law – the rules that have developed based on how states behave. There are elements of both customary law and treaty law in the PERAC principles. There are a lot of principles that are intended as good practice, things that states and other actors should do. There are some that are written more forcefully, many of which reflect existing obligations upon states and other actors, or obligations that are well accepted – these start with shall.

At the start of the PERAC process it was decided that its output should be principles, rather than articles. This reflected the expected pushback from states, and the very broad scope of topics and sources of law and practice that would be involved.

What the PERAC principles do is create a new normative framework that establishes a minimum standard of environmental conduct across the cycles of armed conflict.

The UN Environment Programme’s 2009 report that kick-started the PERAC process is a good guide to the types of law that are relevant to its protection before, during and after conflicts. But while the International Law Commission (ILC) has been working on PERAC, other legal initiatives have also taken place. The most significant has been work by the International Committee of the Red Cross (ICRC) to update its environmental guidelines for militaries. These are International Humanitarian Law rules so they apply during armed conflicts. The ICRC’s process was complementary to the work of the ILC as its guidelines broadly mirror the PERAC principles that apply during conflicts.

Other projects during the same period have looked at the rules protecting water infrastructure, and the standards for assisting victims affected by toxic remnants of war. Another project that may become increasingly relevant in future is that to define the crime of ecocide in international law.

The International Law Commission’s (ILC) main legal roles are the codification and the progressive development of international law. Codification is the precise formulation and systematisation of rules of international law on subjects that have already been extensively covered by state practice, precedent and doctrine. Progressive development encompasses the drafting of legal rules in fields that have not yet been adequately regulated by international law, or sufficiently addressed in state practice.

For some of the PERAC principles, the ILC has also undertaken evolutive interpretation, this relates to changes in how the law is interpreted over time as our societies change. A good example are rules of the law of occupation from the 19^th Century that say how natural resources can be used. The modern concept of sustainability didn’t exist at the time so the ILC reinterpreted these rules to bring them up to date.

In theory, the most extreme forms of environmental damage were already a war crime in international armed conflicts. However, the threshold above which damage becomes a crime has been set unrealistically high and the law has never been properly tested. PERAC hasn’t changed this situation. However, PERAC principle 9 on State responsibility does codify two things: that states should make full reparation for damage caused by internationally wrongful acts, and that this can include the costs of damage to the environment in and of itself.

The expected reception of states to the principles has had a major influence on their development. Because it was anticipated that they would not be viewed favourably by many powerful states, they are perhaps more conservative than might otherwise have been the case. Some states have been opposed from the outset, and have sustained this opposition, arguing that existing protections are adequate. A few states opposed the principles at the outset but have nevertheless engaged constructively with the process, a few have completely changed position to become highly supportive.

Some states have only provided views on the principles that are particularly relevant to them, such as on occupation law, while others engaged very late in the process. Because of their scope, very few states support all of the principles in full. The nuclear weapon states oppose particular principles of International Humanitarian Law that apply to the use of nuclear weapons and the environment, and this has influenced their view of the process.

Protecting the planet is in all our interests so at its simplest the PERAC principles are for all of us. The principles have been informed by our growing understanding of how the environment is harmed in relation to armed conflicts, and which stakeholders can influence this. In this respect they are not only targeted at the militaries of states but also at all branches of a state’s government because some can require the adoption of administrative, judicial, legislative and other measures. Many of the principles are also directed towards a wide range of non-state actors. These include international organisations, non-state armed groups, private military and security contractors, business enterprises and civil society actors.

This will depend on how they are used by the wide range of stakeholders that can influence how the environment is protected across the cycle of armed conflicts. What we do know is that unless they are actively promoted by these stakeholders they are unlikely to have their desired effect. One thing that they have already achieved is that the process to develop them has forced governments to engage on the topic, and to develop and present their positions. However, their future impact will depend upon their universalisation and implementation.

The 27 PERAC principles cover a broad range of topics but there are some themes that are missing. For example, the PERAC principles don’t directly address the environmental impact of specific weapons, such as nuclear weapons, although the consequences of particular military tactics or remnants of war are covered. Nor do the PERAC principles directly address the accountability of non-state armed groups for environmental damage. There was interest in this from a number of states and observers, but the special rapporteur could not find enough existing law to base a principle on.

Ecocide is not addressed because it was not internationally recognised while the PERAC principles were being developed. Finally, climate change does not feature. However, the climate crisis is another important reason to protect the environment in relation to armed conflicts, because a healthy environment helps buffer against the effects of a changing climate.

If the PERAC principles were going to form a new treaty or convention this would be much more straightforward because these instruments typically come with implementation mechanisms. Although a principle on implementation was considered at the final stage of the PERAC process, the International Law Commission felt that implementation should be left up to states. We think the principles are too important to leave up to states and have already been studying how they could be implemented.

One key priority will be for a group of states to show leadership on PERAC and pledge to support its promotion and implementation. This could mean a number of things, including training their own militaries. Other tasks will be to reach out to the many stakeholders for whom the PERAC principles are relevant and working with them to help make sure that they have an impact on the ground. And of course, making the public and policy-makers aware that they exist.

In 2021, the Stop Ecocide Foundation published what it hoped would become the international definition of ecocide. Although a number of states have enshrined ecocide into their domestic legal systems the term is not internationally recognised and so was not included as part of the PERAC principles. The hope is that ecocide will eventually become part of the Rome Statute of the International Criminal Court and be applicable to both conflicts and peacetime.