参照维基，美国在1941年7月26日冻结日本财产，8月一日禁运石油废钢等工业原料。1941年12月6日，珍珠港战役爆发。

https://en.wikipedia.org/wiki/Events_leading_to_the_attack_on_Pearl_Harbor#:~:text=Responding%20to%20Japanese%20occupation%20of,and%20gasoline%20exports%20to%20Japan.

 

Responding to Japanese occupation of key airfields in Indochina (July 24) after an agreement between Japan and Vichy France, the U.S. froze Japanese assets on July 26, 1941, and on August 1, it established an embargo on oil and gasoline exports to Japan