Which of the following targets is considered illegal in warfare?

Civilians that are not hostile are considered illegal targets in warfare because international humanitarian law, including the Geneva Conventions, specifically protects non-combatants from being targeted. This principle aims to limit the impact of armed conflict on those who are not participating in hostilities and to ensure that military operations are conducted in a manner that minimizes suffering and protects innocent lives.

Targeting military installations and enemy combatants is deemed permissible under the laws of armed conflict, as these are legitimate targets that can directly contribute to military objectives. Supplies intended for friendly forces may also be targeted if they are being used to support combat operations. The prohibition against targeting civilians is a fundamental rule aimed at preserving human dignity and protecting those not involved in the conflict.