Legal Definitions - military necessity

Military necessity is a core principle within international law that governs the conduct of armed conflict.

It allows a military force to use coercive measures, such as violence, destruction, or the seizure of property, to achieve a legitimate military objective. However, this principle imposes a strict limitation: the force used must not exceed what is absolutely necessary and proportionate to achieve that objective. In essence, it permits actions that are indispensable for gaining a military advantage or ensuring the safety of one's own forces, but it prohibits any actions that are excessive, wanton, or not directly contributing to the defeat of the enemy.

• Example 1: Destroying a Strategic Bridge

  During a conflict, an army identifies a critical bridge that is the only viable route for enemy reinforcements to reach a contested frontline. Preventing these reinforcements is crucial for the defending army's survival and success in holding their position.

  How it illustrates military necessity: Destroying this bridge would likely be considered an act of military necessity. The action directly serves a legitimate military objective (preventing enemy reinforcement) and is proportionate to the threat. The destruction is limited to the military target (the bridge) and is not excessive, as it is the only effective means to achieve the objective.

• Example 2: Seizing Enemy Communications Equipment

  An advancing military unit discovers a hidden enemy outpost containing sophisticated communication equipment that could be used to coordinate attacks against their forces.

  How it illustrates military necessity: Seizing or destroying this equipment would fall under military necessity. The action directly neutralizes a threat by preventing the enemy from using a vital military asset, thereby contributing to the overall military objective of weakening the enemy's operational capacity. The force used (seizure or destruction of the equipment) is directly linked and proportionate to the military advantage gained.

• Example 3: Targeting a Factory Used for Weapon Production

  In a conflict zone, a factory previously producing civilian goods has been converted by enemy forces to manufacture weapons and ammunition, directly supplying their combat operations.

  How it illustrates military necessity: Targeting and destroying this factory would be justified under military necessity. The factory, having been repurposed for military production, becomes a legitimate military objective. Its destruction directly impairs the enemy's ability to wage war by cutting off their supply of armaments. The action is aimed precisely at a facility contributing to the enemy's military effort, making it a necessary and proportionate measure.