The Great War Begins
President Wilson Asking Congress to Declare War on German, 2 April 1917. Library of Congress # 2002716887. GGA Image ID # 180fff37da
Great Britain and France had been fighting since the beginning of the war in 1914, while Italy had joined in May 1915 and the United States in April 1917. On the other hand, all the European Powers had reached, if not passed, their meridian of strength, whereas the United States could, with a corresponding effort, raise her forces to over ten million. Potentially, she was the most powerful of the associated nations, and only the British fleet's existence brought any rival up to anything like equality. Together the United States and the British Empire were irresistible. So long as they were agreed, any concessions they might make to others would be due, not to fear, but to their sense of justice, desire for peace, and consideration for others' susceptibilities.
The American President, Woodrow Wilson, wisely allowed matters to move slowly, so that when the Germans had filled up the cup of their offenses, it was at the head of a united nation that, on April 6, 1917, he declared war.
The only question still open was what Britain was to do. To prevent the war, Sir Edward Grey proposed to refer all disputes to a European conference; but the Central Powers contemptuously rejected his suggestion.
Thus by April, 1917, the resumption of unrestricted submarine warfare by Germany had brought the United States, the last of the world’s Great Powers, into the war on the side of the Allies.
The greatest war in history resulted from Germany's claim to dominate the world and the inevitable resistance, which such a pretension excited.
German Foreign Minister Arthur Zimmermann sent an encoded message to the President of Mexico. The Germans revealed plans to begin unrestricted submarine warfare, and Germany proposed an alliance with Mexico on January 16, 1917.
President Wilson was deeply stirred by the unexpected Russian miracle. He at once shortened, by two weeks, the date for the convening of Congress and the declaration of war against Germany.
Property can be paid for; the lives of peaceful and innocent people cannot be. The present German submarine warfare against commerce is a warfare against mankind.
During two years preceding our entrance upon war, Germany had been carrying on open warfare against us, within our own borders. For more than thirty years, Germany’s policy of preparatory penetration had been in course.