What does the Law of War principle of "proportionality" prohibit?

The principle of "proportionality" in the Law of War is designed to limit collateral damage during military operations. It prohibits attacks that may cause civilian casualties or damage to civilian property that would be excessive in relation to the anticipated military advantage gained. This means that while combatants are allowed to engage in military operations, they must ensure that any incidental loss of civilian life is not disproportionate to the military objective they seek to achieve.

In practical terms, this principle helps to protect civilians and combatants who are out of combat or not taking an active part in hostilities. It ensures that military operations are conducted with a sense of responsibility towards non-combatants, emphasizing the moral and legal imperatives to avoid unnecessary suffering. The prohibition of excessive incidental loss of civilian lives in relation to the military advantage is a key reason why this answer aligns directly with the principle of proportionality.

Other options present concepts that do not directly pertain to the principle of proportionality in the context of lawful military operations. Therefore, recognizing the relationship between military advantage and potential collateral damage is central to understanding this principle in the Law of War.