You mess with the bull you get the horns

During the beginning of WWI the United States had been content with staying out of the war, it was all European countries and it had no effect on America that was great enough to make us enter the war. However once the Lusitania was sunk it helped push the US into the war. They were outraged that Germans would sink an innocent passenger ship. Once the US declared war the Germans tried to defend their action but the US would not hear their excuses.