Moral equality of combatants
The moral equality of combatants (MEC) or moral equality of soldiers is the principle that soldiers fighting on both sides of a war are equally honorable, unless they commit war crimes, regardless of whether they fight for a just cause. MEC is a key element underpinning international humanitarian law (IHL)—which applies the rules of war equally to both sides—and traditional just war theory.
Source: Wikipedia — Moral equality of combatants (CC BY-SA 4.0)