If only all soldiers deserted there would be no more wars. One day folks will realise that collectively, uniforms represent nothing but the demand for obedience and the absence of conscience. So that folks who are otherwise decent will take a gun, point it at someone, and shoot. As if they are doing nothing bad.
They forget the child that lost its father, the grieving widow, the bereft mother, the future that was lost. All they see is the enemy. because that is what they are trained to do. It's all okay. the flag - a piece of coloured cloth - makes it so.
PTSD. Another name for regret.