How and why did the United States become involved in World War I? What did Woodrow Wilson hope to accomplish in the peace treaty? Why was the outcome with the U.S. Senate so disappointing?
On June 29, 1914, Gavrilo Princip, a Serbian nationalist lobbying for a pan-Slavic nation, murdered the Archduke Franz Ferdinand of the Austro-Hungarian Empire, triggering a series of events that led to the Great War. By the end of the following month, nearly a century of mutual defense alliance treaties had led the majority of Europe to wage war against each other. Naturally, in response to the assassination of their archduke, Austria-Hungary declared war on Serbia, counting on the support of its ally, Germany. Because Russia had previously promised to defend Serbia if the need were to arise, they were immediately brought in. Germany then preemptively declared war on Russia before the country or its associate, France could act. Germany later took it even further, invading Belgium, bringing in Great Britain. The final partner in the Central Powers, the Ottoman Empire, joined the war when they attacked Russian (Corbett et al., 2017).
The advent of a world war brought new military technology: artillery, tanks, airplanes, machine guns, barbed wire, poison gas, etc. One of these inventions was the infamous German unterseeboot (an "undersea boat" or U-boat). In early 1915, a fleet of these submarines was deployed to attack any British ships in response to the naval blockade Great Britain had imposed on Germany. Instead of surfacing and permitting civilians and/or crew to surrender, the Germans directly violated international law by attacking without warning from beneath the water. On May 7th of that year, the British passenger ship, the RMS Lusitania, was fired upon on its way from New York to Liverpool, killing 1,200 civilians (of which 128 were American). While this murder of innocent Americans was not enough for President Wilson to break his policy of neutrality, businessmen and government officials began to pressure the executive office to take action. Thus, in 1916, the year prior to the next elections, Wilson agreed to a "preparedness campaign," approving the National Defense Act that doubled the size of the U.S. Army and the Naval Appropriations Act that expanded the U.S. fleet (Corbett et al., 2017).
Many factors, including Germany's use of submarine warfare, played a part in the eventual U.S. engagement in the Great War. One aspect of the decision was economic in nature. Not only was Great Britain America's most important trading partner, Germany enjoyed American exports as well. However, within the first two years of the war, though British exports rose from $750 million to $3 billion, German exports dropped from $350 million to $30 million. Additionally, ethnic divisions were growing between native-born Americans and more recent immigrants. The final element that "broke the camel's back" was the so-called Zimmerman telegram that was intercepted by British intelligence. This message, from German Foreign Minister Arthur Zimmerman and the German ambassador to Mexico, was meant to encourage Mexico to join the war effort on the German side. Germany urged Mexico to invade the United States in exchange for land lost during the Mexican-American War. By April 2, 1917, Wilson had asked Congress for a declaration of war (Corbett et al., 2017).
By November of 1918, an armistice was declared and the peace process was started. As early as January of that year, Wilson had already formulated a plan for postwar peace and presented it before a joint session of Congress. At this meeting, he proposed two main ideas: his Fourteen Points and the League of Nations. Wilson's Fourteen Points called for "openness in all matters of diplomacy and trade, specifically, free trade, freedom of the seas, an end of secret treaties and negotiations, promotion of self-determination of all nations, and more" (Corbett et al., 2017). Yet, when these thoughts were announced during the Paris Peace Conference from the end of 1918 to mid-1919, the Treaty of Versailles that resulted was completely different. The only point of Wilson's included was the creation of the League of Nation and the associated Article X. This article stipulated that those in the league would defend all other member nations against all military threats (Corbett et al., 2017).
When the president returned to the United States, he faced the task of gaining approval for the treaty. Indeed, two-thirds approval from the U.S. Senate was needed for the final ratification. However, several groups such as the Irreconcilables and Reservationists had entirely different ideas for the treaty and eventually, the accord and subsequent amendments were rejected. Thus, the U.S. never became an official signatory of the Treaty of Versailles and technically remained at war with Germany until years later with the passage of the Knox-Porter Resolution. Finally, Wilson was left embarrassed and dejected that his own nation vetoed the plan that he, himself, had come up with and convinced the other world powers to agree to (Corbett et al., 2017).
Corbett, P. S., Janssen, V., Lund, J. M., Pfannestiel, T., Waskiewicz, S., Vickery, P. 2017. U.S. History. Houston: OpenStax.