Full Idea
We must stop reassuring soldiers that they act permissibly when they fight in an unjust war, provided that they conduct themselve honorably on the battlefield by fighting in accordance with the rules of engagement.
Gist of Idea
Soldiers cannot freely fight in unjust wars, just because they behave well when fighting
Source
Jeff McMahan (Killing in War [2009], 2.8)
Book Reference
McMahan,Jeff: 'Killing in War' [OUP 2009], p.95
A Reaction
This culminates McMahan's arguments against the moral equality of combatants, and against the sharp division of justice of war from justice in war. How rare it is for philosophy to culminate in a policy recommendation!