The major global event that the sinking of the Lusitania contributed to was the United States entering World War I. In 1915, the British ocean liner was torpedoed by a German U-boat, resulting in the death of 1,198 passengers, including 128 Americans. This incident generated public outrage in the U.S., influencing public opinion against Germany and intensifying hostilities. The sinking was pivotal in shifting U.S. foreign policy from isolationism to interventionism, culminating in American entry into the war in 1917 and altering the course of the conflict.