Why did Germany start sinking American ships in World War 1?

Germany began sinking American ships during World War I primarily due to its policy of unrestricted submarine warfare. This strategy aimed to blockade Britain and weaken its supply lines, as Germany sought to cut off resources to its enemy. The sinking of American vessels, including the Lusitania in 1915, heightened tensions between the U.S. and Germany, ultimately contributing to the U.S. decision to enter the war in 1917. Germany hoped to defeat the Allies before American troops could significantly impact the conflict.