My position is that even if any particular administration were capable of such perfidy, the execution would involve so many people that the coverup would never hold. The government can’t even keep the lid on legitimate national security secrets. How in blue blazes could it keep the lid on something like this?
As for Pearl Harbor, a belatedly delivered coded message does not culpability make, especially on the part of FDR. That a faction inside his administration could have sat on this message for a time is entirely believable, but is a far cry from what the government is accused of on and leading up to 9-11.
I have already stated that FDR’s role in Pearl Harbor is not proven. However, my father was an intelligent, contemporary observer of the people and events of that conflict, and his sense of the direct culpability of FDR in deliberately starting the war with Japan is completely consistent with other behaviors of FDR during the period. See http://hnn.us/articles/89.html
Therefore, there is plausibility, and that should at least have the effect of entering the debate with caution rather than bravado.