Following the assassination of Archduke Francis Ferdinand in the summer of 1914, Europe’s major powers—linked into two rival alliances—mobilized their armed forces and plunged Europe into World War I. By the end of 1917, more than a million French soldiers lay dead. France’s British, Russian, and Italian allies had suffered similar losses, as had their German, Austro-Hungarian, and Ottoman enemies. Still, after more than three years of war, none of these powers had publicly declared its war aims or had seriously sought a negotiated end to the war. This secrecy and determination to fight to the bitter end frustrated repeated American efforts to negotiate peace in 1916. After German submarines sank several U.S. merchant ships, President Woodrow Wilson persuaded Congress to declare war on Germany, and the United States joined the Allied coalition.