There has been no smoking gun nor first person testimony to indicate FDR knew of the attack. I think there was the opinion that Japan was going to attack somewhere..but Hawaii was a stretch. Even if he had known..and put the fleet to sea..the event might have been worse. The Japanese battle fleet might have located the ships and carriers at sea and sunk them where salvage was not possible.
This is a poorly titled article. Like most people have commented, we know that Japan was to blame for bombing Pearl Harbor.
That being said, it is a fact that American intelligence was “reading” Japanese encrypted mail long before the bombing. There was plenty in their “mail” which told of the oncoming attack. Now the question remains as to who knew and who told whom what.
Personally, I think if the President did know and made a calculated risk, in hind sight, I think he made the right choice. I wasn’t there, so I can’t judge him.
Did FDR know it was coming on Dec 7th? Probably not.
Did the US expect that there might be an attack? Yes. Many books talk about the fact that having sanctions against Japan was seen as risking war. The US military had some training games based around it. However, it is also pretty clear they didn’t view Japan as a major threat, or war as likely.
If you read books about Patton and others, they expected that there would be war against Japan, but many figured the Phillipians would be the first place attacked.