Related Rule
Islamic Republic of Iran
Practice Relating to Rule 44. Due Regard for the Natural Environment in Military Operations
In 1991, during a debate in the Sixth Committee of the UN General Assembly on protection of the environment in armed conflict, the Islamic Republic of Iran stated:
Turning to the law on the protection of the environment, … the general principles of customary international law clearly contained specific rules on the protection of the environment. One such rule was the obligation of States not to damage or endanger the environment beyond their jurisdiction, a rule which had been enshrined in numerous international and regional agreements.
With regard to the application of environmental law in time of war, … the relationship between a party to the conflict and a neutral State was essentially governed by the law in time of peace and, consequently, belligerent parties had an obligation to respect environmental law vis-à-vis non-belligerent States. There was no universally accepted rule concerning the application of international law on the protection of the environment to belligerent parties, and some argued that the relationship was governed by the law of armed conflict, which meant that with the outbreak of war, the application of rules on the protection of the environment was suspended. However, others argued that in such cases, under treaty law and customary law, international legal rules protecting the environment were neither suspended [n]or terminated, since the law of armed conflict itself tended to protect the environment in time of war. 
Islamic Republic of Iran, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/ 46/SR.18, 22 October 1991, §§ 30–31.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, the Islamic Republic of Iran stated:
[The] prohibition of the use of nuclear weapons, due to their huge destructive and modifying effects, could also be understood from the rules of international law relating to the environment. First of all, reference can be made to Principle 21 of [the] 1972 Stockholm Declaration on Human Environment which, as a customary rule, stipulated that States are responsible for any acts in their territory having adverse effects on the environment of other States. The same idea is also reflected in Principle [2] of [the] Rio Declaration of 1992. It can be argued that, while States are prevented from such conducts in their own territory, they are duly bound to refrain from any such acts against other States.
The progressive development of international environmental law in recent years has resulted in the adoption of a series of treaties, such as:
– Vienna Convention for the Protection of the Ozone Layer (1985)
– United Nations Framework Convention on Climate Change (1992)
– Convention on Biological Diversity (1992)
which is indicative of the awareness of [the] international community and the emergence of an opinio juris concerning the preservation of the environment. Therefore, the use of nuclear weapons, having the most destructive effects on the environment, is a great concern of [the] international society. 
Islamic Republic of Iran, Written statement submitted to the ICJ Nuclear Weapons case, 19 June 1995, pp. 4–5, § c.
The Report on the Practice of the Islamic Republic of Iran states that the Iranian Government holds Iraq responsible for attacking oil tankers in the Gulf and polluting the sea during the Iran–Iraq War. The Islamic Republic of Iran also denounced Iraq for using chemical weapons, which resulted in the pollution of the air, water, soil and consequent effects on the ecosystem. The report adds that it is the Islamic Republic of Iran’s opinio juris that “the environment must be protected against pollution during armed conflict”. 
Report on the Practice of the Islamic Republic of Iran, 1997, Chapter 4.4.