Man longs for peace but his governments send him to war in the name of causes just and unjust. It seems that every generation must wake up, at some point, to scan the headlines and to read of the latest bloody battle that has bereaved families of combatants on both sides.

Ninety-five years ago, the nations of Europe (the U.S. was not yet in the conflict) tore out the heart of their coming generation in the horrible trench warfare of World War I. Great armies took and gave back and took again small stretches of barren land. There was little progress during month after month of the exceptionally bloody conflict.

In the first year of war, 1914, a candle appeared and familiar carols in another language were heard from the German side. The British troops sang their own carols and soon the two sides met, briefly, in No Man’s Land. The next day they resumed killing each other.

On Christmas Eve 1915, again the British hunkered down in their trenches and the Germans, not far away,...