There was an oil embargo, that was the stated reason for Japans move against the US. Lets not forget that Japan invaded Manchuria and Korea simply because they felt a military adventure or two would solve their economic woes, they were partially right. The idea was to blackmail the US into a settlement, to give them a dose of the same gunboat diplomacy the region had been on the receiving end of in the unequal treaties. and in doing so settle an old score.
Of course if the US didn't sue for peace the whole exercise would be doomed from the start, which is how it worked out.