Thinking about it, unlike OTL there probably won't be a formal embargo with the sort of "do this or else" there was OTL. However, with the USA at war, the needs of the USA (and allies) will take priority, and the stuff Japan needs will be the stuff the USA needs and that will be that. I can see the USA simply telling Japan that due to the wartime needs, all critical supplies are requisitioned, and contracts for the future nullified - so sorry. While this is less of a humiliation for Japan, as opposed to giving in under threat, the reality remains the same - get oil and other raw materials or face collapse in 12-24 months versus end the war in China. With the USA pumping up its military at a high rate 6+ months sooner than OTL, the window for Japan to "do something" is even narrower. With the probable shift of at least some of the US Pacific Fleet to the Atlantic, Japan may strike earlier even if the KB has only four large carriers ready instead of six. In any case, I don't see the internal politics of Japan operating much differently.