A century ago this month, the U.S. Congress declared war on Imperial Germany. The secure New World foolishly joined the Old World slaughterhouse, consigning more than 117,000 Americans to death.

The chief outcome of the war was to sweep away several reasonably benign if imperfect "ancien regimes" while loosing various totalitarian bacilli. The so-called Great War's unfinished business was finally settled only in World War II, after consuming as many as 80 million more lives.

By April 1917, Europe had been at war almost three years. The resulting horror vindicated America's decision to remain aloof.