In April 1917, more than two and a half years into the bloodiest war the world had yet seen, nearly half of the 9 million soldiers, sailors and airmen, and the 5 million civilians who would be killed in the First World War already lay dead. Some 65 million men were at arms, more than all previous wars combined. Day after terrible day, some 5,000 men died on average. The names of once unknown places where millions died rang out like mournful bell tolls: Somme, Verdun, Gallipoli, Tannenberg, Marne, Ypres, Passchendaele. Despite the unprecedented violence of the first truly mechanized war, the opposing forces of Germany, the Austro-Hungarian Empire and their allies—the Central Powers—and the Allied armies of France, Great Britain, Russia, and Italy, rarely advanced in this awful war of attrition.
Only one great power still stood aloof from the carnage. The United States had remained at peace, following President Woodrow Wilson’s dictate that Americans “must be neutral in fact as well as in name” and “impartial in thought as well as in action.” Even the infamous torpedoing of the British liner the Lusitania, drowning 1,198 people including 128 Americans, and the sinking of multiple American freighters by German U-boats could not arouse the nation for war. Although by and large sympathetic to the Allied nations, the U.S. maintained an army smaller than the Great War combatants lost in a typical month’s fighting. Its modern naval fleet had not trained for the realities of undersea warfare practiced by its potential enemies. And the dawning third dimension of the battlefield, the air war, barely figured into military thinking; the nation supported air forces smaller than Bulgaria’s.
As the battle for European dominance became a world war, no country remained an island; the globalization that has grown suspect today had already sprung fully upon the world in the form of ocean-going international trade. Demand for American products and raw materials from around the world had transformed the nation into an industrial powerhouse. As increasing numbers of ships carrying American-made goods went to the bottom of the ocean, though, more and more voices called for the country to fight to maintain freedom of the seas. Former President Theodore Roosevelt led the chorus calling upon America to enter the battle against what they decried as the Central Powers’ lawlessness.