An interesting book somewhat related to this is Poilu, the notebooks of a French soldier who served through most of the war. He was an avowed socialist who never fired his weapon at the enemy and encouraged the soldiers under him (when he was a corporal) to do the same. One of his stories was about a period later in the war when the soldiers on both sides of the trenches in his area had reached an “accommodation” where they refused to shoot at each other. One day a high-ranking officer visited, saw the situation, picked up a soldier’s rifle and shot dead an enemy soldier lounging in full view across no-man’s land. This precipitated a resumption of “normal” warfare in the area but almost got the officer killed - by his own soldiers.