SHC, I draw your attention to this:
Did a little (okay, a lot) of emphasizing to show you just exactly what is throwing you off. Namely an offhand remark in a document outlining some very sound tactical recommendations.
Now your idea that Roosevelt let it (the attack on Pearlharbor) on purpose... How I know it's a tactically and strategically stupid idea?
I can just imagine the scenario: The year is 1942 and I'm president of the Unitedstates of America, and Commander in Chief of the armed forces. The population are weary from a previous world war that taken a lot out of America. War looms again in the horizon as Germany makes a march to conquer the world, killing all who stand in their way.
And I receive reliable intel that assets I can easily protect in Hawaii are being targeted by Japan, who have been rattling their sabers (as it were) at us and our British allies alongside their German allies. My immediate response would be to authorize a preemptive strike on their fleet, use their thwarted attack as an example these guys aren't so tough and we can take them...
SHC only a complete moron would entertain the notion of a stand down in an anticipated attack.