I think he is saying that FDR stopped selling oil to Japan, in such a way that Japan was provoked to attack the US.

That’s why they attacked Pearl Harbor in the first place: to neutralize the US navy threat in the Pacific while seeking for new oil sources down South.

They were at war with many countries, but they weren’t at war with the US specifically up until that point.

And by the way the US sold oil to Japan to profit from their war machine in Russia, Manchuria and China. It wasn’t until the very end that they stopped selling it.