World War I was a bloodletting so vast and unprecedented that for a generation it was known simply as the Great War. Casualty lists reached unimagined proportions as the same ground -- places like Ypres and the Somme -- was fought over again and again. Other major bloody battles remain vivid in memory to this day: Gallipoli and the Battle of Jutland are but two examples. Europe was at war with itself, and the effect on Western civilization was profound,...