Franklin D. Roosevelt's Address to the Congress Asking That a State of War Be Declared Between the United States and Japan, www.loc.gov. December 8, 1941.
Radio broadcast, 29 Dec. 1940. According to Walter Isaacson and Evan Thomas, The Wise Men (1986), this slogan was picked up for Roosevelt's address after it was used in conversation by John McCloy, who had gotten it from Jean Monnet.