Doug - You thought that the Japanese would not go to war over FDR's 1941 embargo on their overseas sources of oil and steel???

(Heh! I know that's probably not what you meant, but...well, I think that FDR would have been VERY surprised and quite frustrated if the Japanese had decided to just give up, cave in, pull their armies out of China, mothball their navy, abandon their overseas efforts at empire, and consent to being a has-been as a major power in the Pacific...)

They did nothing of the kind, of course. They reacted precisely as expected, and went to war. This is how you get the country into a war when neither Congress nor the general public really want one.

You then act morally outraged and disbelieving when the inevitable happens....very effective for mobilizing the country.