Frequently Asked Questions: IHL and the escalating conflict in the Middle East

International humanitarian law (IHL), also known as the “laws of war”, is the set of international rules that regulates armed conflicts, including the behaviour of States and other parties to conflict.

IHL is distinct from the body of international law that governs the legality of the resort to armed force between States which includes the United Nations (UN) Charter. 

IHL is multifaceted, comprised of different rules that regulate distinct aspects and situations arising in armed conflict. For example, it sets limits on how military operations can be carried out. Many of the rules governing the conduct of hostilities are anchored in the cardinal principles of distinction, proportionality, and precaution. Other sets of rules regulate how persons affected by armed conflict must be treated, including those who find themselves in the hands of a party to the conflict —for instance when they are detained or when they live under occupation. 

Three fundamental principles of IHL regulate the conduct of hostilities, i.e. the fighting between the parties to the conflict: distinction, proportionality and precautions. These are customary in nature and must be complied with in all circumstances by all parties - States, non-state armed groups and civilians taking a direct part in hostilities - in all armed conflicts - both international and non-international. Certain categories of persons and objects such as medical units, transports and personnel, objects indispensable to the survival of the civilian population and  installations containing dangerous forces, are afforded additional, heightened protection (see below question on the protection of civilian infrastructure). 

The principles and rules governing the conduct of hostilities apply whenever fighting takes place as part of an armed conflict: whether on land (ground operations), in the air (air warfare) or at sea (naval warfare), as well as in the cyber domain (cyber operations) and in outer space. 

The IHL principles and rules that govern the conduct of hostilities aim to protect the civilian population from the effects of hostilities. They do so by striking a balance between military necessity and humanity, imposing prohibitions and restrictions on the weapons, means and methods of warfare that parties to the conflict may use.

The principle of distinction requires that parties to the conflict must always distinguish between combatants and civilians, and between military objectives and civilian objects, such as homes, civilian infrastructure, and the environment. Parties may only direct their attacks against combatants, never against civilians; and they may only target military objectives, never civilian objects. Indiscriminate attacks, namely attacks that are not directed at specific military objectives as required, that cannot be so directed, or whose effects cannot be contained as required by international humanitarian law, are also strictly prohibited. Equally prohibited are acts or threats of violence the primary purpose of which is to spread terror among the civilian population, and the use of starvation of the civilian population as a method of warfare.

Attacks directed against a combatant or another military objective must respect the principle of proportionality. This means that it is prohibited to launch an attack that may be expected to cause incidental loss of civilian life, injury to civilians, and/or damage to civilian objects that would be excessive in relation to the concrete and direct military advantage anticipated. In other words, a military objective may be attacked only after an assessment leading to the conclusion that civilian losses and damage are not disproportionate the military advantage foreseen.

The principle of precautions requires all parties to a conflict to take constant care to spare the civilian population and civilian objects from the effects of military operations. Given the significant risk of harm to civilians whenever executing an attack, IHL imposes detailed obligations to those planning, deciding on or carrying out attacks. In particular, all feasible precautions must be taken to

- Verify that targets are military objectives;
- Avoid, and in any event to minimize, incidental loss of civilian life, injury to civilians and damage to civilian objects;
- Assess whether the attack may be expected to violate the rule of proportionality;
- Cancel or suspend an attack if it becomes apparent that it would violate the principles of distinction or the rule of proportionality;
- Give effective advance warning of attacks which may affect the civilian population.

IHL also requires parties to the conflict to protect civilians and civilian objects under their control against the effects of attacks.  In cities, military and civilian people and objects are often intermingled. For parties involved in hostilities in urban or other populated areas, this intermingling presents important challenges, both militarily and in terms of avoiding civilian harm. Because urban warfare endangers civilians in specific ways, the protection afforded by the principles and rules of IHL is critical. 

Civilians and civilian objects are protected against attack and must not be targeted. IHL requires parties to armed conflict to always ensure their attack is directed against a specific military objective. This requires reasonable certainty as to the status of the target, as well as constant verification measures to achieve it. The targeting of people and objects requires an individual assessment in each and every case.

Insofar as persons are concerned, combatants (i.e., members of State armed forces – other than medical and religious personnel – and members of armed wings of non-State armed groups) may be targeted, unless they are hors de combat (wounded, sick, shipwrecked, incapacitated, have indicated a clear intention to surrender, or are otherwise in the power of the enemy). Civilians are protected against attack, unless and for such time only as they directly participate in hostilities. Political and administrative officials with no military status or command function are civilians and may not be targeted on the basis of their political or administrative function alone.

Insofar as objects are concerned, civilian objects are protected against attack and only military objectives may be targeted. These are objects that make an effective contribution to military action by their nature, location, purpose or use, and an attack on which offers a definite military advantage in the circumstances ruling at the time. In order to constitute a military objective, an object must be closely connected to the fighting. Objects that merely support the war effort, including financially, are not lawful targets. 

Infrastructure that enables the provision of essential services to civilians are in principle civilian objects, and as such are protected by all the IHL rules protecting the civilian population and civilian objects from the effects of hostilities. Importantly, this includes prohibitions against direct, indiscriminate and disproportionate attacks, and the rules on precautions in attack and  precautions against the effects of attack. (see above How does IHL protect civilians and civilian objects against the danger of hostilities?)

The services essential for the civilian population and other protected persons during armed conflict are interconnected and interdependent, which means the disruption of one can have domino or reverberating effects on others and result in multiple services being disrupted or even collapsing. For instance, electricity supply is needed to ensure the delivery of water and sanitation, solid waste disposal and the cold chain. Hospitals and food production and distribution capacities are then dependent on a reliable supply of safe water, sanitation, and electricity.

Attacks expected to damage critical infrastructure will likely affect a large part of the civilian population beyond the weapon's impact area and for a period well beyond the immediate aftermath of the attack. Such harm is relevant for both proportionality and precautions in attack insofar as it has a causal link to the attack and is reasonably foreseeable at the time of the attack.

IHL also affords special, heightened protection to certain types of critical infrastructure, notably hospitals and other medical facilities and transports, objects indispensable to the survival of the civilian population, and works and installations containing dangerous forces, in addition to cultural property and the natural environment. Pieces of energy infrastructure critical to the effective operation of other indispensable objects also enjoy special protection. Every special protection regime is different, but it often entails protection against operations other than attacks, and some degree of protection even in case such objects constitute military objectives.

Energy infrastructure, namely critical infrastructure that enables the provision of energy to civilians (such as networks of electricity-, fuel- and gas-related infrastructure) are also in principle civilian objects and as such may not be attacked. They become military objectives only if they make an effective contribution to military action (e.g., a power station providing electricity to a military barracks) and attacking them offers a definite military advantage in the circumstances. Sweeping or anticipatory classification of the entire electricity grid (or other energy network) of a country or area under enemy control as a military objective is prohibited. Moreover, IHL forbids attacks against pieces of energy infrastructure if the sole purpose is to degrade an adversary’s economic capacity, even if they are indirectly sustaining their war-fighting capability, to force the adversary to the negotiating table, to influence the will of the population, or to intimidate political leaders. 

In some cases, critical infrastructure (and other civilian objects) may be used simultaneously for both civilian and military purposes. Such so-called “dual-use” objects may become military objectives provided they meet the criteria required under IHL (see the definition of military objective above in How does IHL protect civilians and civilian objects against the danger of hostilities?). However, those planning and deciding to attack such infrastructure must take into account the incidental harm on civilians (including the impact on the civilian use of the object) that would result from the attack, take all feasible precautions to avoid or at least minimize it, and ensure that it is not excessive.

IHL imposes numerous prohibitions and restrictions on the development and use of specific weapons, under both treaty and customary law (see rules 70 to 86 of the ICRC customary IHL study). The use of all weapons, whether or not specifically restricted, must in any case comply with all the principles and rules governing the conduct of hostilities, including the prohibitions against direct, indiscriminate and disproportionate attacks, and the rules on precautions in attack (see above How does IHL protect civilians and civilian objects against the danger of hostilities?).

While there is no general prohibition under IHL against using heavy explosive weapons in populated areas, their use in such areas is very likely to have indiscriminate effects. This underpins the long-standing call by the ICRC and the broader International Red Cross and Red Crescent Movement to all States and non-state armed groups parties to armed conflicts to avoid the use of heavy explosive weapons in populated areas. These weapons should not be used in populated areas unless sufficient mitigation measures are taken to limit their wide area effects and the consequent risk of civilian harm.

90 states have now endorsed the 2022 Political Declaration on Strengthening the Protection of Civilians from the Humanitarian Consequences arising from the use of Explosive Weapons in Populated Areas . It is the first instrument of its kind committing States to, among others, review their military policy and practice and to restrict, or refrain as appropriate from the use of explosive weapons in populated areas, where such use may cause civilian harm. When properly implemented, it can contribute significantly to alleviating civilian suffering and strengthening respect for IHL.

With a view to reducing human suffering, the Arms Trade Treaty (ATT) prohibits State Parties from authorizing the export, transit and other transfers of conventional arms, ammunition and related parts and components covered under the Treaty in the knowledge that they would be used to commit war crimes or other international crimes (Art 6). The ATT also prohibits States Parties from exporting arms or other items covered by the Treaty  where there is an overriding risk that these could be used to commit or facilitate a serious violation of IHL or human rights(Art 7). Certain regional instruments also restrict arms transfers on humanitarian grounds and require such an assessment 

All States, even those not party to the ATT, have an obligation to refrain from transferring weapons to a party to an armed conflict where there is a clear risk that this would contribute to the commission of IHL violations. In addition, arms transferring States must do everything reasonably in their power to prevent and stop IHL violations committed by their arms trading partners (Art 1 common to the 1949 Geneva Conventions). States that supply weapons to a party to an ongoing armed conflict can be considered particularly influential in ensuring respect for IHL, owing to their ability to provide or withhold the means by which IHL violations may be committed. Conditioning, restricting or halting transfers of weapons are practical means in the power of arms transferring States to prevent and stop IHL violations.

Read more about arms transfers to parties to armed conflict.

While IHL does not explicitly prohibit or restrict the use of AI in military applications, it does restrict its development and use and places strict constraints on AI when it is integrated into weapon systems or used in some way to conduct warfare. As such, and like any new technology of warfare, AI must be capable of being used and must only be used in compliance with existing principles and rules of IHL (see above How does IHL protect civilians and civilian objects against the danger of hostilities?).

Against the backdrop of the growing development of and reliance on AI-related technologies in the military domain, it is important to recall that IHL obligations bind humans. It is humans who must ensure the lawfulness of attacks that they plan, decide upon or execute, and they remain accountable for those determinations. These assessments include whether attacks comply with the conduct of hostilities principles and rules, namely distinction, proportionality and precautions in attack, which cannot be outsourced to machines.

This does not mean that commanders and combatants cannot or should not use tools, including AI decision-support systems, to perform tasks such as collateral damage estimations or calculating the blast radius of munitions. However, such outputs should be understood as sources of information or computational indicators, rather than legal assessments of whether an attack complies with IHL. Accordingly, these systems and tools must be designed and used to support, rather than hinder or replace, human decision-making.

Read more about ICRC’s position on the use of AI in armed conflict.

Data centres used solely for civilian purposes, including those provided by private technology companies, are civilian objects. They must not be the object of attack.

Specific servers or data centres may be used to store data collected by armed forces, including intelligence, and data centres can provide the computing power needed to run AI models used by armed forces, or the digital space to host AI decision support systems. Whether and in which cases such data centres may become military objectives requires a case-by-case analysis. Unless and for such time as they qualify as a military objective they must not be attacked. Even if a specific data centre, or parts thereof, qualify as a military objective, the rules and principles of proportionality and precautions in attack must still be respected. Applying these principles and rules requires assessing both foreseeable direct and indirect civilian harm, such as harm to civilians working in the data centers, and harm to civilian populations reliant on the data centers for the proper functioning of essential services, and taking all feasible precautions to avoid and in any event minimize it. (see above How does IHL protect civilians and civilian objects against the danger of hostilities?)