Although, granted, the admiral who led the attack, Isoroku Yamamoto, knew it was suicide from the start, judging by the excerpts from the numerous conversations and diary entries he had. "I fear all we have done is to awaken a sleeping giant and fill him with a terrible resolve." or "In the first six to twelve months of a war with the United States and Great Britain I [can expect to] win victory after victory. But then, if the war continues after that, I have no expectation of success."