Pearl Harbor Attack
"Imperial Japanese military leaders appear to have had mixed feelings about the attack. Fleet Admiral Isoroku Yamamoto was unhappy about the botched timing of the breaking off of negotiations. He is rumored to have said, 'I fear all we have done is awakened a sleeping giant and filled him with terrible resolve'. Even though this quote is unsubstantiated, the phrase seems to describe his feelings about the situation. He is on record as having said, in the previous year, that 'I can run wild for six months ... after that, I have no expectation of success.'
"Yamamoto had said, regarding the imminent war with the United States, 'Should hostilities once break out between Japan and the United States, it is not enough that we take Guam and the Philippines, nor even Hawaii and San Francisco. We would have to march into Washington and sign the treaty in the White House. I wonder if our politicians (who speak so lightly of a Japanese-American war) have confidence as to the outcome and are prepared to make the necessary sacrifices?'"
Isoroku Yamamoto to Shigeharu Matsumoto (Japanese cabinet minister) and Fumimaro Kondoye (Japanese prime minister), quoted in Ronald Spector, Eagle Against the Sun: The American War With Japan (Vintage, 1985).
^National Geographic mini-biography of Isoroku Yamamoto