Just War Theory Helps Defines Morality in Conflict, A Brief Explainer

“Gassed” by
John Singer Sargent

I am Catholic and I developed most of my Catholicism on studying the theological teachings of St. Thomas Aquinas and St. Augustine of Hippo. Two saints who contributed and influenced Just War Theory, the laws of war, and the moral philosophy of warfare. My Catholic Confirmation Saint is St. Michael the Archangel, the leader of the army of God. I also served 4 ½ years in the US Army Infantry as a Platoon Leader and Executive Officer. I found it critical, prior to me enlisting in the Army in 2013, to study and build a moral background so that I may perform my job to the best of my abilities. I have decided to share what I have learned throughout the years in a brief summary:

Just War Theory examines the moral justifications to go to war and to engage in war. Jus ad bellum and Jus in bello are the Latin translations for those theories. Jus ad bellum defines what justifies going to war while Jus in bello defines how combatants should behave while engaged in war.

Jus ad Bellum — Right to War

The act of war an immoral behavior. Which is why you better have a damn good reason for it.

Jus in Bello — Right in War

The principle of proportionality demands combatants engage in proportional levels of destruction that are related to a clearly defined objective. War will require combatants to destroy. Destroy lives, property, and kill other human beings. Therefore, that immoral behavior requires you do so proportionally. That you are only destroying and killing what is necessary. Not for fun, not for vengeance, not for retaliation, not for a message. Regarding the bigger picture, this requires combatants to engage using only necessary force to end the conflict as soon as possible. On the ground, combatants must engage in military actions that do not unnecessarily kill or destroy. This requires combatants to have discipline and sympathy to not engage in wanton or reckless destruction. If an enemy takes the lives of 10 of your civilians, it does not justify taking the lives of 100 of their civilians.

The Pragmatism of Just War Theory

U.S. Army Veteran. M.A. International Relations from University of Chicago. Voter. Volunteer. I write to inform my friends as best I can.