The Environment in War

The Rome Statute of the International Criminal Court 1998, article 8, paragraph 2(b)(iv), makes it a war crime intentionally to launch an attack in the knowledge that it will cause widespread, long-term and severe damage to the natural environment which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated. The same cumulative threshold, plus a proportionality test.

The customary rules

The Court stated the position in the Legality of the Threat or Use of Nuclear Weapons advisory opinion, ICJ Reports 1996, p. 226.

Facts. The General Assembly asked whether the threat or use of nuclear weapons is in any circumstance permitted under international law. Several States argued that the environmental treaties in force prohibited their use outright.

Held. The Court did not accept that environmental treaties are intended to deprive a State of the exercise of its right of self-defence, but it held that States must take environmental considerations into account when assessing what is necessary and proportionate in pursuit of legitimate military objectives, and it stated that the general obligation of States to ensure that activities within their jurisdiction and control respect the environment of other States or of areas beyond national control is now part of the corpus of international law relating to the environment.

Why it matters here. It is the authority for two propositions at once: environmental obligations do not disappear in war, and they operate through the ordinary rules of necessity and proportionality rather than as an absolute bar.

The soft law

Stockholm Principle 26: man and his environment must be spared the effects of nuclear weapons and all other means of mass destruction.

World Charter for Nature 1982, General Principle 5: nature shall be secured against degradation caused by warfare or other hostile activities.

Rio Principle 23: the environment and natural resources of people under oppression, domination and occupation shall be protected.

Rio Principle 24: warfare is inherently destructive of sustainable development; States shall therefore respect international law providing protection for the environment in times of armed conflict and cooperate in its further development as necessary.

The International Law Commission's principles on protection of the environment in relation to armed conflicts, adopted in 2022, address the whole cycle: measures before, during and after conflict, protected zones, the responsibility of corporations, occupation, and remnants of war. They are not a treaty.

Reparation, and the one worked precedent

After the invasion of Kuwait in 1990 and the burning of some six hundred oil wells, the Security Council affirmed Iraq's liability under international law for environmental damage and the depletion of natural resources resulting from the unlawful invasion and occupation. The United Nations Compensation Commission was established and awarded very large sums, including for environmental damage and for the cost of monitoring and assessment.

That is the only large-scale worked precedent for reparation of wartime environmental damage, and it is the example to give. Its basis was the unlawfulness of the invasion under the general law, not the Additional Protocol threshold.

Worked example

An air campaign destroys an oil refinery, releasing crude into a river system used by a neighbouring State.

• Was the refinery a military objective? If it fuelled the opposing forces, probably yes.
• Was the attack proportionate? The environmental damage counts in the proportionality assessment, on the nuclear weapons opinion.
• Did it meet the Article 35(3) threshold? Widespread, long-term and severe, cumulatively. River contamination lasting a few years probably does not.
• Does State responsibility apply anyway? If the use of force was unlawful, yes, and reparation is owed for all the damage caused by it, including the environmental damage. That is the Kuwait route.
• Does the neighbouring State have a claim? Yes, as an injured State under article 42, for the harm on its territory.

Notice that the strongest route is the general law, not the specialist environmental provisions. That is the practical lesson of this chapter.

Quick revision

• Three bodies of law: armed conflict, State responsibility, environmental treaties. Keep them apart.
• Additional Protocol I Articles 35(3) and 55: widespread, long-term and severe, cumulatively; never applied.
• Environmental Modification Convention 1976: widespread, long-lasting or severe; using the environment as a weapon.
• Rome Statute article 8(2)(b)(iv): the same cumulative threshold plus proportionality.
• Nuclear weapons opinion 1996: environmental considerations enter necessity and proportionality; the Principle 21 obligation is part of the corpus.
• Kuwait: Security Council affirmation of liability, and the United Nations Compensation Commission's awards.

Test yourself

1. Why have Articles 35(3) and 55 of Additional Protocol I never been applied? Because their threshold is cumulative, widespread and long-term and severe, with long-term understood as decades, so almost no act of war meets it.

2. How does the Environmental Modification Convention differ from those provisions? Its threshold is disjunctive, widespread, long-lasting or severe, and it prohibits the hostile use of environmental modification techniques as a weapon rather than incidental damage caused by ordinary means of warfare.

3. On what basis was Iraq held liable for environmental damage in Kuwait? On the general law of State responsibility, because the invasion and occupation were unlawful, so reparation was owed for all resulting damage including environmental damage. The Security Council affirmed the liability and the United Nations Compensation Commission assessed it.