Which principle of LOAC emphasizes the need for only necessary engagement during military operations?

The principle that emphasizes the need for only necessary engagement during military operations is Military Necessity. This principle dictates that military actions must be necessary for achieving a legitimate military aim and that they should be limited to what is needed to accomplish that aim. This means that any engagement should be directly linked to military objectives and should avoid causing unnecessary suffering or destruction.

Military Necessity serves as a guiding framework to ensure that actions taken during warfare are justified by the requirements of the military campaign. It balances the need to achieve operational goals with the obligation to uphold humanitarian standards, ensuring that the methods used in warfare do not exceed what is needed to secure a legitimate military advantage.

This principle helps in establishing a standard to determine whether an action is appropriate in the context of armed conflict, thereby reinforcing the ethical dimension of military operations and aiming to protect non-combatants and civilian infrastructure as much as possible.