Why didm the us join world war 1?

The United States joined World War I in April 1917 primarily due to unrestricted submarine warfare by Germany, which threatened American shipping and lives. The sinking of ships like the Lusitania, combined with the interception of the Zimmermann Telegram—where Germany sought an alliance with Mexico—fueled public and political support for entering the war. Additionally, the U.S. aimed to protect its economic interests and promote the idea of making the world "safe for democracy."