On October 7, 1940, Lieutenant Commander Arthur McCollum of the Office of Naval Intelligence submitted a memo to Navy Captains Walter Anderson and Dudley Knox (whose endorsement is included in the following scans). Captains Anderson and Knox were two of President Roosevelt's most trusted military advisors.
The memo, scanned below, detailed an 8 step plan to provoke Japan into attacking the United States. President Roosevelt, over the course of 1941, implemented all 8 of the recommendations contained in the McCollum memo. Following the eighth provocation, Japan attacked. The public was told that it was a complete surprise, an "intelligence failure", and America entered World War Two.