What did the memorandum from October 1940 demonstrate?

Answer: The McCollum memo, also known as the Eight Action Memo, was a memorandum, dated October 7, 1940, sent by Lieutenant Commander Arthur H. McCollum, who "provided the president with intelligence reports on ... every intercepted and decoded Japanese military and diplomatic report destined for the White House" in his capacity as director of the Office of Naval Intelligence's Far East Asia section.