Which principle of the Law of War justifies actions taken in warfare?

The principle of military necessity is fundamental in justifying actions taken in warfare. It dictates that military operations are permissible only when they are necessary to achieve a legitimate military objective. This means that any attack or action must be aimed at furthering military goals and should be directed toward enemy forces or resources. The military necessity principle aims to ensure that every action taken during conflict serves a strategic purpose and minimizes unnecessary suffering or damage to civilian life and property.

In this context, any military action must be proportional to the military advantage gained, ensuring that it does not exceed what is required to accomplish the mission objectives. Therefore, actions justified under military necessity must meet a balance where they are both necessary and directed toward achieving a valid military goal.