Hello
I recently read Johnathan Parshall and Anthony Tully's Shattered Sword: The Untold Story of The Battle of Midway. Really informative and a book I highly recommend if you're interested in the material.
Of all the background information leading up the actual battle, the simultaneous invasion of the Aleutian Islands, the huge dispersal of the combined fleet, the unrealistic time table, the thing about Yamamoto's plan for a decisive battle with the US Navy that stuck out the most to me is that Kidō Butai and its aircraft carriers, (in this battle composed of CarDiv1's Akagi and Kaga and CarDiv2's Hiryū and Sōryū) was expected to soften up Midway and any enemy naval forces encountered until Yamamoto's main body, including the battleships Yamato, Nagato, and Mutsu could show up and blow away whatever was still afloat.
I know that ever since the Japanese forced the Russians to sue for peace in the Russo-Japanese War following the Japan's incredible naval victory at Tsushima, the Japanese Navy had become obsessed with the idea of ending wars through a decisive naval battle, but why did Yamamoto think the way to achieve that in 1942 still lay with the battleship?
Aircraft carriers had been critical in Japan's success in the war thus far, and Yamamoto and the top brass seemed to be in agreement that the USN's aircraft carriers had to be eliminated, which suggests they all recognized how important such vessels were, so why were they given a support role in the planning for this decisive engagement?
Considering that the prevailing Japanese notion was that the Americans would have to be coaxed into fighting, and the superior speed and range of aircraft carriers, how exactly were the battleships supposed to contribute? It seems like they'd only be able to sink aircraft carriers that had already been effectively eliminated as threats: those that could no longer launch planes or move quick enough to escape. In which case, it seems like Kidō Butai's own battleships should be sufficient to sink them rather than waiting for combined fleet to show up.
I know a major part of the answer to this can be summed up as "Naval doctrine," but I'm hoping I'm missing something that makes the expectation that an operation intended to wipe out aircraft carriers would be determined by battleships make a bit more sense.
Thank you
Its a multifaceted issue. But it all circles back to Yamamoto being a bit less able to break out of the gun club than maybe is appreciated. While Midway was only half the battle the IJN thought they would have on their hands.
From your OP it seems that the missing part is that the IJN assumed the carriers wouldnt sortie from Pearl alone. They figured the gun line would go with them, since thats what they would do. Either for a naval action, or as part of a counter landing. They were not aware that TF-1, the Pearl survivor battleships was then off Southern California under VADM Pye. Who himself may have had something of a nervous breakdown over perceived Japanese threat to the mainland at that time. Japanese efforts to get any sort of good intel on who was in Pearl in the lead up had been frustrated or countered, another ? for them to deal with.
So now youve got 2 major problems to deal with. Being to beat the US carriers, who in the meantime as covered in summary in Shattered Sword, were making a fine mess of things for Japan, but then also beat the gunline of battleships. Which even Prince of Wales/Repulse aside, nobody really wanted to just assume a well defended task force could be taken down just from the air. To say nothing of the realities of time, distance, and servicing time making it difficult to get more than 2 strikes a day in if you need to send our spotters for the enemy too.
He thus never conceived of a final decisive battle that wasnt finished in sight of each other and fought out between the surface combatants in line astern like the days of old. Hardly shocking as he of course was witness to the great decisive victory at Tsushima.
And in keeping with how the IJN culturally assumed it would go. The idea for the great final battle would be something like:
Day 0: Enemy position fixed by subs, attrition begins. Ideally of course as part of a long series of attacks if in friendly territory, or over a prepared line of subs if on the offensive like at Midway.
Day: 1 morning spotting with aircraft, strike arrives late morning, ideally with another in the afternoon. Meant to establish air superiority and begin chipping away at the gun line.
Night: Light surface forces harry and achieve preferred tactical position.
Day 2: Gun line closes and finishes off US gun line which is stripped of carrier protection.
We also should note the IJN wasnt expecting to be so separated when the battle came, the intel coup of the US, meant that the battleships were in no position to actually do their job. Had Fletcher and Spruance been forced to worry about a 2nd task force with the big 3 to deal with, that changes things. That was another failure on the part of the IJN, made in part for logistic concerns, and to not restrict Nagumo.
While we also cant deny that simply giving the battleships a bone factored in too. Telling them they get to put in the killing blow is much better for morale than saying, "we will see what scraps the carriers leave".
The problem with your question is that it puts the cart before the horse - Midway is really what established^(1) the superiority of aircraft carriers in naval doctrine to begin with. Until that time carriers were thought to have questionable reliability (due to their dependence on good weather) and hadn't yet proven their potential against surface ships, being commonly used against land targets - the IJN's ostensible target at Midway was the naval facility and airfield. Recall that in 1940 the converted HMS Glorious had been sunk by battleships (albeit while outmatched), and the periodic loss of aircraft carriers to submarines, and it should be clear why naval leaders would have relegated carriers to a supporting rule.
^(1) Churchill says in his memoirs that he knew at the outset of WW2 that carriers had far greater potential than anyone else in the admiralty realized and would supplant battleships as the linchpin of naval force projection, but I've never been sure how much credence to give that.