The truce was an "away fixture" for the British, but an occupation for the French. When a British unit that had fraternized with Germans on Christmas Day marched back from the line, French women lined the streets to spit on them, disgusted they would socialize with the invaders of their country.

The Christmas Truce was not universally observed. Some battle-hardened British units, like the Second Grenadier Guards who had recently suffered heavy losses, immediately shot German soldiers who attempted to fraternize. Post-truce infighting even broke out between participating and non-participating British units.

For decades after WWI, the Christmas Truce was a minor historical footnote. It was resurrected in the 1960s by Joan Littlewood's anti-establishment play, "Oh, What a Lovely War," which framed the event as a powerful symbol of the war's futility and the humanity of ordinary soldiers.

The truce was not purely about goodwill. Some soldiers used the opportunity for tactical gain. One British officer shared a cigar with a German sniper, learned of his reputation and position, and noted it down with the explicit intention of targeting and killing him the following day.

The surge in interest around the 2014 centenary wasn't just historical curiosity. It reflected modern anxieties about the Iraq and Afghanistan wars and a focus on veterans' mental and physical health, making the truce a powerful symbol for the horror and futility of conflict.

The modern belief that deep economic ties between the U.S. and China will prevent war echoes Norman Angell's 1910 bestseller, "The Great Illusion." That book argued European economies were too intertwined for a major war, a theory tragically debunked just four years later by World War I.

Popular memory imagines a spontaneous, mutual halt to fighting. In reality, German troops began the truce by placing hundreds of candle-lit Christmas trees on their trench parapets and singing carols, prompting a curious and initially cautious response from the British.

The truce profoundly affected 19-year-old Henry Williamson, convincing him of the kinship between British and German soldiers. This pacifist conviction tragically warped over time, leading him to become a fascist and an admirer of Adolf Hitler, whom he mistakenly believed was a fellow peace-seeking trench veteran.

Beyond exchanging gifts, the truce's most profound moments came from conversation. British soldier Henry Williamson was staggered to see German grave markers honoring soldiers who died "for freedom" and to hear from Germans that they, too, believed their cause was a just defense of their homeland.