Proportionality (law) in the context of "Armed conflict"

A war crime is a violation of the laws of war that gives rise to individual criminal responsibility for actions by combatants in action, such as intentionally killing civilians or intentionally killing prisoners of war, torture, taking hostages, unnecessarily destroying civilian property, deception by perfidy, wartime sexual violence, pillaging, and for any individual that is part of the command structure who orders any attempt to committing mass killings (including genocide or ethnic cleansing), the granting of no quarter despite surrender, the conscription of children in the military, and flouting the legal distinctions of proportionality and military necessity.

The formal concept of war crimes emerged from countries fighting and the codification of the customary international law that applied to warfare between sovereign states, such as the Lieber Code (1863) of the Union Army in the American Civil War and the Hague Conventions of 1899 and 1907 for international war. In the aftermath of World War II, the war-crime trials of the leaders of the Axis powers established the Nuremberg principles, such as that international criminal law defines what is a war crime. In 1899, the Geneva Conventions legally defined new war crimes and established that states could exercise universal jurisdiction over war criminals. In the late 20th century and early 21st century, international courts extrapolated and defined additional categories of war crimes applicable to a civil war.

The law of war is the part of international law that regulates the conditions for initiating war (jus ad bellum) and the conduct of hostilities (jus in bello). Laws of war define sovereignty and nationhood, states and territories, occupation, and other critical terms of law. Among other issues, the modern laws of war address the declarations of war; acceptance of surrender and the treatment of prisoners of war; the principles of distinction, as well as military necessity and proportionality; and the prohibition of certain weapons that cause unnecessary or excessive suffering.

The law of war is considered distinct from other bodies of law—such as the domestic law of a particular belligerent to a conflict—which may provide additional legal limits to the conduct or justification of war. The term law of war, or jus in bello, overlaps to some degree with opinio juris (also referred to as customary law), but refers to a very specific body of international law composed of customary and treaty-based law.

Distinction (principle of distinction) is a principle under international humanitarian law governing the legal use of force in an armed conflict, whereby belligerents must distinguish between combatants and protected civilians. Combatant in this instance means persons entitled to directly participate in hostilities and thus are not afforded immunity from being directly targeted in situations of armed conflict. Protected civilian in this instance means civilians who are enemy nationals or neutral citizens outside of the territory of a belligerent power.

Article 51.3 of the 1977 Additional Protocol I to the Geneva Conventions explains that “civilians shall enjoy the protection afforded by this section, unless and for such time as they take a direct part in hostilities.” Distinction, proportionality, and precaution are important factors in assessing military necessity in that the harm caused to protected civilians or civilian property must be proportional and not "excessive in relation to the concrete and direct military advantage anticipated" by an attack on a military objective.

"Necessary in a democratic society" is a test found in Articles 8–11 of the European Convention on Human Rights, which provides that the state may impose restrictions of these rights only if such restrictions are "necessary in a democratic society" and proportional to the legitimate aims enumerated in each article. According to the Council of Europe's handbook on the subject, the phrase is "arguably one of the most important clauses in the entire Convention". Indeed, the Court has itself written that "the concept of a democratic society ... prevails throughout the Convention". The purpose of making such claims justiciable is to ensure that the restriction is actually necessary, rather than enacted for political expediency, which is not allowed. Articles 8–11 of the convention are those that protect right to family life, freedom of religion, freedom of speech, and freedom of association respectively. Along with the other tests which are applied to these articles, the restrictions on Articles 8–11 have been described as "vast limitations", in contrast to American law which recognizes nearly unlimited right to freedom of speech under the First Amendment.

A war crime is a serious violation of the laws and customs applicable in armed conflict, known as international humanitarian law (IHL) and the laws of war, which gives rise to criminal responsibility under international law. Examples of actions committed by combatants in the conduct of war that can give rise to individual criminal responsibility include, but are not limited to: intentionally killing civilians, torture, taking hostages, unnecessarily destroying civilian property, deception by perfidy, wartime sexual violence, pillaging, the granting of no quarter despite surrender, the conscription of children in the military, ordering any attempt to commit mass killings (including genocide or ethnic cleansing), and flouting the requirements of distinction, proportionality and military necessity.

The formal concept of war crimes emerged from countries fighting and the codification of the customary international law that applied to warfare between sovereign states, such as the 1863 Lieber Code of the Union Army in the American Civil War and the Hague Conventions of 1899 and 1907 for international war. In the aftermath of the Second World War, the war crime trials of the leaders of the Axis powers established the Nuremberg principles, such as that international criminal law defines what is a war crime. In 1899, the Geneva Conventions legally defined new war crimes and established that states could exercise universal jurisdiction over war criminals. In the late 20th century and early 21st century, international courts extrapolated and defined additional categories of war crimes applicable to a civil war.