the Japanese leaders who were US-educated (including Konoe and Yamamoto) absolutely knew that attacking the US would steel the Americans' resolve against Japan:

the Japanese leaders who were US-educated (including Konoe and Yamamoto) absolutely knew that attacking the US would steel the Americans' resolve against Japan: > In the first six to twelve months of a war with the United States and Great Britain I will run wild and win victory upon victory. But then, if the war continues after that, I have no expectation of success.