It was a bizarre decision: the secure New World voluntarily joined the Old World slaughterhouse, consigning more than 117,000 Americans to death for no intelligible reason.

The chief outcome of the war was to sweep away several reasonably benign if imperfect "ancien regimes" while loosing various totalitarian bacilli. All too naturally, even, seemingly, inevitably, emerged communism, followed by fascism and Nazism. The so-called Great War's unfinished business was finally settled only in World War II, after consuming as many as 80 million additional lives.

In April 1917 Europe had been at war almost three years. On June 28, 1914 a Serbian terrorist killed Archduke Ferdinand, the heir to the Hapsburg throne of Austro-Hungary. Vienna accused Belgrade of complicity in the crime, which in fact was promoted by Serbian military intelligence. But the Russian Empire came to Serbia's defense. Imperial Germany sided with its ally, Austro-Hungary. France backed its treaty partner, the Russian Tsar.