WW1: Why and how did Hoover justify going to war?

Hoover didn't push for entry into WWI because he was not president for another decade. Woodrow Wilson was the president at the time and he entered the war because: 1. The sinking of the Lusitania (sp) which was a commercial ship which killed Americans due to Germany's unrestricted submarine warfare 2. The Zimmerman note which asked Mexico to declare war on the United States and in return Germany would give it back its lost territories 3. the U.S. was already allied with Great Britain and was selling them arms.