The defenders of a territory under attack aren't put in that position by any real choice of their own - none that is practical anyway. Being able to live with

The defenders of a territory under attack aren't put in that position by any real choice of their own - none that is practical anyway. Being able to live with themselves after the conflict is over, being able to re-integrate them into civilized society, is an important facet of maintaining a peaceful society. You don't plan for everything going well (no one ever goes for war). You plan for when things don't.