Just War Part 7: Jus Ad Bellum & Jus In Bello

Once these major contributions to Just War thinking by warriors (knights) and the Church (Augustine and Aquinas) were made and largely accepted among Catholics of the Middle Ages, the tradition of Just War was taught as having two components: the right to go to war and the right conduct of war.  These were labeled in Latin as “jus ad bellum” and “jus in bello.”

The criteria of jus ad bellum were:

1.War had to be declared by a “legitimate” authority.

2.War had to be declared with right intention, for a just cause

3.War had to be the last resort.

These criteria limited war somewhat but also made it possible, though exceptional, for a just war to exist.  A just war had to meet these criteria.  Most wars, because of the severe requirements of these criteria, were viewed as unjust.  In addition to meeting the criteria of jus ad bellum, a war had to meet the requirements of jus in bello, further decreasing the possibility of a war being deemed “just”.

The criteria of jus in bello were:

1.The immediate objective of force couldn’t be to kill but to restrain.

2.Soldiers who surrendered could not be killed.

3.Non-combatants (civilians, the unarmed) could not to be attacked directly.

4.Indiscriminate force and weaponry could not be used (indiscriminate meaning without a specific limited target)

5.Unnecessary suffering was prohibited.

“While in a formal or technical sense this doctrine is essentially medieval and Catholic, in more loose and diffuse terms it remains to this day the dominant military ethos of the Western world.”(1) Those are the words of an ethicist in the 1960’s, a time when these criteria influenced our thinking on war but obviously did not reign supreme over it.  Something must have changed in our understanding of these criteria, between their authoring in the Middle Ages, when wars declared “just” were exceptions, and the twentieth century, when just wars were often waged by and approved of by the majority of American Evangelical Christians as “just”.

For now it suffices to point out that in time the criteria for just war has obviously loosened, losing much of the original restriction of force found in the jus ad bellum and jus in bello.  These criteria evolved in some way allowing for the killing of “non-combatants” and use of “indiscriminate force” at Hiroshima and Nagasaki, for example.  What I’ll contend in my next post on Just War is that the evolution or erosion of these criteria is not a modern American phenomena but instead began shortly after the ink dried on the words “jus in bello” and “jus ad bellum.” It began when Christopher Columbus brought war to the Americas in the sixteenth century.

1. Paul Peachy, “New Ethical Possibility,” Interpretation 19 (January 1965): 26-27