Civilian casualties

Civilian casualties is a military term describing civilian or non-combatant persons killed, injured, or imprisoned by military action. The description of civilian casualties includes any form of military action regardless of whether civilians were targeted directly. This differs from the description of collateral damage that only applies to unintentional effects of military action including unintended casualties.

Civilian casualties therefore include victims of atrocities such as the Nanking Massacre committed on a civilian population where hundreds of thousands of men were slaughtered, while girls and women ages ranging from 10 to 70 were systematically raped or killed by Japanese soldiers in 1937. Another example is the My Lai Massacre (thảm sát Mỹ Lai) that was committed by U.S. soldiers during the Vietnam War on hundreds of unarmed Vietnamese civilians. Such military action, which has the sole purpose of inflicting civilian casualties is illegal under modern rules of war, and may be considered a war crime or crime against humanity.

Other kinds of civilian casualties may involve the targeting of civilian populations for military purposes, such as the atomic bombings of Hiroshima and Nagasaki, which killed over 100,000 civilians. The legality of such action was at the time governed by international law found in the Hague Regulations on Land Warfare of 1907, which state "the attack or bombardment, by whatever means, of towns, villages, dwellings, or buildings which are undefended is prohibited". Also relevant, were the Hague Draft Rules of Air Warfare of 1922–1923, which state "air bombardment is legitimate only when is directed against a military objective". The Rome Statute defines "intentionally directing attacks against the civilian population" to be illegal, but only came into effect on July 1, 2002 and has not been ratified by every country.

The ethics of civilian casualties
Many modern nations' views on the ethics of civilian casualties align with the Just War theory, which advocates a system of proportionality. An act of war is deemed proportional in Just War theory if the overall destruction expected from the use of force is outweighed by the projected good to be achieved. This view is a war-adapted version of utilitarianism, the moral system which advocates that the morally correct action is the one that does the most good.

However, moral philosophers often contest this approach to war. Such theorists advocate absolutism, which holds there are various ethical rules that are, as the name implies, absolute. One such rule is that non-combatants cannot be attacked because they are, by definition, not partaking in combat; to attack non-combatants anyway, regardless of the expected outcome, is to deny them agency. Thus, by the absolutist view, only combatants can be attacked. The philosopher Thomas Nagel advocates this abolutist rule in his essay War and Massacre.

Finally, the approach of pacifism is the belief that war of any kind is morally unjust. Pacifists sometimes extend humanitarian concern not just to enemy civilians but also to combatants, especially conscripts.

Civilian casualty ratio
The civilian casualty ratio in an armed conflict is the ratio of civilian casualties to combatant casualties or total casualties. The measurement can apply either to casualties inflicted by a particular belligerent or to casualties in the conflict as a whole.

According to a 2001 study by the International Committee of the Red Cross, the civilian to soldier death ratio in wars fought since the mid-20th century has been 10:1, meaning ten civilian deaths for every soldier death.