That is interesting, Ellenpoly. Back when Bywater wrote that book all the key naval planning (both American and Japanese) was built around battleships. Aircraft carriers were seen only as a scouting and secondary raiding force, it was battleships which were expected to fight the decisive battles.

It was the British carrier plane attack on the Italian fleet at Taranto in 1941 that changed that perspective! The Japanese admiral Yamamoto immediately saw that carrier aircraft could alter the strategic balance and supplant battleships as the decisive striking factor. Hence...Pearl Harbour.

Roosevelt had deliberately aggravated the Japanese in such a way as to precipitate a conflict by the end of '41, and fully expected such a conflict, but seems not to have expected them to hit as far afield as Pearl Harbour. On the contrary, I think he expected them to hit the Phillipines, Hong Kong, Malaya, and the Dutch East Indies (which they did...in addition to hitting Pearl Harbour).

The Japanese were expected to have an initial advantage in the early fighting, but the Phillipines was expected to hold out, despite Japanese landings, until the US fleet could concentrate its battleships and arrive off those islands...there to meet the Japanese and defeat them, mainly with big guns.

Even had the Japanese won that battle, American mass production was expected to inevitably defeat them soon enough, in further battles. This latter assumption was entirely correct. There was no way Japan could win a long conflict with the USA. They could only hope to win some of the early battles.

And they did just that...up until Midway. The Americans were kicked into the aircraft carrier age by Japan when it crippled their battleship fleet at Pearl Harbour. It is to the credit of the American navy that it adapted to the new carrier tactics as quickly as it did. Within less than 2 years of Pearl Harbour the Americans had the largest and most efficient aircraft carrier force in the World, and they have maintained it ever since.