Legal Definitions - jus belli

Jus belli refers to the international laws and customs that govern the conduct of warfare once a conflict has begun. It outlines the acceptable and prohibited actions for countries engaged in hostilities (known as belligerents), as well as defining the rights and responsibilities of nations that choose to remain neutral during a conflict.

Essentially, while other legal principles might address whether it is lawful to go to war in the first place (jus ad bellum), jus belli focuses on how that war must be fought, aiming to minimize suffering and protect non-combatants.

• Example 1: Treatment of Prisoners of War

  During an armed conflict between Country A and Country B, soldiers from Country B are captured by Country A's forces. Under jus belli, specifically as codified in the Geneva Conventions, Country A has a duty to treat these prisoners humanely. This includes providing adequate food, shelter, and medical care, and prohibiting torture or cruel treatment. This example illustrates jus belli by defining a clear duty of a belligerent power (Country A) regarding the conduct of its forces during wartime.

• Example 2: Protection of Civilian Infrastructure

  In a conflict, Country X is targeting military installations within Country Y. Jus belli dictates that Country X must take all feasible precautions to avoid targeting civilian areas, such as hospitals, schools, or residential neighborhoods, and must distinguish between military objectives and civilian objects. Intentionally bombing a civilian hospital, even if it is near a military base, would be a violation of jus belli. This demonstrates how jus belli sets limits on the actions of belligerent powers to protect non-combatants and civilian property during hostilities.

• Example 3: Respect for Neutral Territory

  When two nations, Alpha and Beta, are engaged in war, a neighboring country, Gamma, declares itself neutral. Under jus belli, Country Gamma has a right to have its neutrality respected, meaning neither Alpha nor Beta can conduct military operations within Gamma's borders, fly military aircraft over its airspace without permission, or use its territory as a base for attacks. In turn, Gamma has a duty not to provide military assistance to either side. This scenario highlights how jus belli defines the rights and duties of neutral nations, ensuring their sovereignty is respected while also requiring them to uphold their non-involvement.