From: Sacramento, CA
From the stand point of we knew for sure before PH is total bunk. The other point is in 1940 if you cut off a nation from oil, meaning that once their reserves run out they will be defenseless. It would only be a matter of time before they are going to get oil from somewhere somehow. This has been slightly discussed before but IMHO it was foolish to think that Japan would just back down and leave China and Indochina. So in my view the moment we started the oil embargo we should have acted as if war was imminent or a definite. General MacArthur's total negligence in getting caught 24 hours after PH was almost criminal in it's nature. What he would have been able to do once the Japanese landed was in reality probably not much more than he did. The getting caught with his pants around his ankles when Congress is getting ready to declare war was a different story.I'm also not a fan because of fighting to deny Wainwright the CMOH because he surrendered. Given the fleet and armies state even without PH would have almost certainly meant the loss of the Phillipines.
I would like to add some supporting evidence to the contention that the US government was aware of the risk of war but chose to accept it as the lesser of two evils.
By coincidence, I have just begun re-reading History of United States Naval Operations in WWII, Volume III; The Rising Sun in the Pacific. Samuel Eliot Morison indicates that one of the main reasons for heasitation in starting the embargo was precisely the thought that Japan would go after the Dutch East Indies. On Page 36, the book states " Mr. Grew warned his government in 1938 that if Japan were deprived of oil she would move south and take what she wanted in Burma and Sumatra. Consequently, neither an oil embargo nor any other economic sanction should be imposed until and unless the United States was 'prepared to see them through to their logical conclusion, and that might mean war'." Note that Mr. Grew was the US Ambassador to Japan, and thus in a position to speak with some authority.
I think the hope was that the remnants of the moderates would try to regain control of the Japanese military. Given that in 1922, the Diet voted to cut off funds for Japanese intervention in the Russian Civil War (used as an excuse to effectively take over part of Siberia), this hope was less ridiculous at the time than it now appears in hindsight. Even then, it was optimistic, but maybe not insane.