WAR BROKE OUT in Europe in July of 1914, war on a scale that had never been seen before, a war run by efficiency experts and waged with factory-made munitions, a war without limit or mercy. Machines slaughtered the masses. Europe fell to its knees. The United States rose to its feet. The Great War brought the United States into the world. It marked the end of Europe’s reign as the center of the Western world; that place, after the war, was held by the United States.