It would seem or non-historian hater has forgotten the Japanese announced policy of The Greater East Asia Co-Prosperity Sphere. The Japanese planned the Sphere in 1940 to create a Great East Asia, comprising Japan, Manchukuo, China, and parts of Southeast Asia, that would, according to imperial propaganda, establish a new international order seeking "co prosperity" for Asian countries which would share prosperity and peace, free from Western colonialism and domination
The Americans were fully aware that the Japanese were preparing to attack the Western colonies....but that Japan first needed to solidify her conquests in China. China was another step on their empires conquest of Asia starting with Taiwan in 1895, then Korea, the German colonies in WWI, then Manchuria and at the time China and later Indo-China.
The Americans were also fully aware that their naval/air strenght backed by their industrial capacity would crush Japan if the Japanese attacked. The embargo was an attempt to stop the war before it began.