You think FDR was actively helping the Axis cause?
While the country was isolationist, FDR wanted to find a way to get us involved in order to help the Allies other than the under the table help we were already providing them.
He got it with Pearl Harbor.
Only I do not think he imagined the horror that would happen as a result.
Whether or not he knew or not is moot. There was a huge collapse of common sense among both politicians in high office and the military.