The operation had obviously been extremely well thought out and well organized; if it hadn't been, such a large task force would not have been able to proceed so far under the cloak of nearly complete secrecy. Nevertheless, even after the mission was well under way, various Japanese officers involved expressed misgivings or worries about its efficiency and likelihood of success. For example, Isoroku Yamamoto, the supreme commander of Japan's fleets, did not like the idea of sending so many submarines in advance of the main fleet. He worried that they might be too easily detected and tip off the Americans to the assault. But his superiors in Tokyo, who wrongly believed that the subs would do more damage than airpower, overruled him.

Another Japanese officer, Gunichi Mikawa, commander of the battleships and cruisers in the task force, was...