Franco Prussian generals trained in the art of war by men who mastered it at the feet of men who answered to Napoleon and the Duke of Wellington. Waging war with 19th century tactics and 20th century weapons. Tactics that called for massed formations of men marching against each other in an orgy of shooting, stabbing, and clubbing met twentieth century weapons designed to prevent face to face battle. The evolution from saber to muzzle loading blunderbuss to machine gun took less than one hundred years. Military tactics were tragically slower to evolve. The result: millions marched and ran and dove into a hail of machine gun fire. Trenches were dug, the men climbed in and the slaughter was on. This was the Great War. Battle lines shifted a few hundred yards this way and that at a cost of millions of young lives. The magnitude of the carnage was beyond anything humanity had ever experienced. The simultaneous birth of mass communication and urbanization allowed the horror to be communicated contemporaneously and shared by the general population.
This was no historical event communicated to the privileged few. This was a horror vicariously experienced on a massive scale. And it was a war no one wanted. Germinated in an arms race, nations bent on saving face built in Empires now fading moved armies to borders to show their strength and courage. Generals trained in military academies developed plans for war and defense. Triggered by the assasination of a low level member of a once royal family, the Generals threw their great plans into motion and swept across borders on foot and horseback before anyone could say "wait a minute." Year after year the armies slaughtered each other until they literally ran out of men. The American's arrival shifted the balance through sheer increase in numbers. When it was over millions were dead and no one knew why.