Full Idea
At the time when war was a profession, fighting men had a morality whereby any act of war, in accordance with the customs of war, and contributing to victory, was legitimate and right.
Gist of Idea
When war was a profession, customary morality justified any act of war
Source
Simone Weil (Is There a Marxist Doctrine? [1943], p.173)
Book Reference
Weil,Simone: 'Oppression and Liberty' [Routledge 1955], p.173
A Reaction
Note the caveat about 'customs', which were largely moral. See the discussion of killing the non-combatant prisoners in Shakespeare's 'Henry V'.