Due to attack on passenger and merchant ships
When the Germans, declared unrestricted submarine warfare, the US issued a sharp protest to this policy, saying that it was an indefensible violation of neutral rights, and threatened to hold Germany accountable. Unrestricted Submarine Warfare. The use of unrestricted submarine warfare was announced by Germany on January 9th, 1917. The use of unrestricted submarine warfare was to have a major impact on World War One as it was one of the main reasons why America joined the war. On this day in 1916, Germany responds to a demand by U.S. President Woodrow Wilson by agreeing to limit its submarine warfare in order to avert a diplomatic break with the United States. The United States later declared war on German ally Austria-Hungary on December 7, 1917. World War I Trenches in France. Germany’s resumption of submarine attacks on passenger and merchant ships in 1917 became the primary motivation behind Wilson’s decision to lead the United States into World War I. First used during World War I, this type of warfare was highly controversial and deemed a breach of the rules of war. Resumption of unrestricted submarine warfare by Germany in early 1917 was a key reason the United States entered the conflict. Used again in World War II, it was generally accepted by all combatants though technically banned by the 1930 London Naval Treaty. Publisher. A+E Networks. On this day in 1917, the lethal threat of the German U-boat submarine raises its head again, as Germany returns to the policy of unrestricted submarine warfare it had previously suspended in response to pressure from the United States and other neutral countries.
http://www.answers.com/Q/What_was_Woodrow_Wilson's_reaction_to_the_German_submarine_warfare_campaign http://www.historylearningsite.co.uk/world-war-one/naval-warfare-and-world-war-one/unrestricted-submarine-warfare/ http://www.history.com/this-day-in-history/germany-agrees-to-limit-its-submarine-warfare https://history.state.gov/milestones/1914-1920/wwi http://militaryhistory.about.com/od/glossaryofmilitaryterms/g/unrestsubwar.htm http://www.history.com/this-day-in-history/germany-resumes-unrestricted-submarine-warfare
why did the us protest germany use of submarine warfare