A mistake often made by people of good will – who have no personal, first-hand experience of a particular armed conflict – is to assume that the combatants on both sides are, likewise, people of good will.
Sometimes they are. But then again, sometimes there really are barbarians at the gate!
I like to think that people emerge from the womb without animosity toward others, but a charismatic leader and/or religion preaching hatred can soon change that, and deprogramming takes much longer than programming, if indeed it is possible at all.
Many people are, so to speak, unsalvageable.