PS: FDR began sending supplies to the USSR before pear harbor despite its mass murder and atrocities across Eurasia and extreme unpopularity of the Soviet government with the US public. The embargo with Japan was made for geopolitical reasons and any "humanitarian" argument is post hoc.
EDIT: Remarkably, President Herbert Hoover remained politically active in the post-FDR media landscape and his account of the events and of FDRs actions leaves little room for doubt about FDRs aims in his foreign policy with Japan.
https://www.hoover.org/research/freedom-betrayed-herbert-hoo...