December 13, 1941
: From the Diary of Rear Admiral Giichi Nakahara:
On the strength of our success at Pearl Harbor we should occupy Hawaii now, some people say. It goes without saying that it is the best policy to take Hawaii to decide the future of the Pacific. If we lose a day in occupying the Islands, our operation to capture them will be so much the more difficult. Our experience at Wake Island shows this. However, if we fail in this, the tables will be turned favorable to the United States again in a minute. So it cannot be done so hastily.
1. The US has yet fairly strong sea power in her hand. And air fighters will be reinforced day after day. Consider how strong they were in defending Wake Island with their fighters!
2. England has yet a predominant sea power. We know how it will be when we are attacked in our rear. Our Malay operation will end in a fiasco, if this should happen.
3. It must be borne in mind that Russia might attack our rear.
4. It will be disadvantageous for us to keep and maintain the Hawaiian Islands in our hands after capturing them. So that it can be thought of and should be well considered to have them, if we have to take into consideration the relations with the United States only.
But this is a dangerous idea. We must not take an inch if given an inch. It is necessary to put the idea into practice after our operational line that runs through Burma, Sumatra, Java, New Guinea and the Solomons is secured for us. It demands at least three months to acquire this line. Then Hawaii will have been reinforced so that our operation will not go as we want it to. After all, we have to destroy more of the enemy's sea power and await the chance of our absolute success. For the time being, the United States will not try her active trans-ocean operation. And the US will try to evade war with the USSR [Note: IMO, the diarist probably meant to write Germany], dividing the former's naval power into 60% in the east and 40% in the west) of course the situation will make her concentrate her whole power in one part).
THEN THE CONCLUSIONS WILL BE AS FOLLOWS: The Japanese Navy should decoy out the British Fleet and merchant marine ships by attacking them in the Indian Ocean (for India is her treasure-house; so if it is charged by us, England will make desperate efforts in defending her). And we should try to shake hands with Germany through the Suez Canal. And on the other hand, we should try to battle the US intention of making cross-ocean operations by pushing forth our operation in New Guinea and the eastern part of the Pacific Ocean; at the same time we should decoy out the US fleets and destroy them by our submarines and planes of the Combined Fleet. During this period we should have to send many submarines in order to intercept US supply there as well as to cut off US reinforcements of naval strength there. Thus the rehabilitation of Hawaii will be hindered. (Dillon)