Which principle governs the conditions under which States may resort to the use of force, guiding international law and military actions?

• A. Jus ad bello
• B. The principles of LOAC/Law of War
• C. Jus ad bellum
• D. Title 10

Answer: (C)

The main idea here is understanding when a state is legally allowed to use force. That governs the right to go to war, which is captured by jus ad bellum. It sets the conditions under which resorting to force is permissible—principles like self-defense recognized by the UN Charter, or authorization by the UN Security Council, along with considerations such as necessity, proportionality, and last resort before taking action. This concept guides both international law and how militaries decide to act in the first place.

In contrast, the LOAC or Law of War concerns how force is actually used once a conflict begins—rules about protecting civilians, distinguishing between military targets and noncombatants, proportionality of attacks, and humane treatment of prisoners. Jus ad bellum determines whether war is allowed to start; LOAC governs conduct during the war. The term jus ad bello is sometimes used, but the standard, widely taught term for permission to engage in war is jus ad bellum.