I thought the point of Midway was to push the USN further east to prevent another Doolittle raid which was a major embarrassment for the IJN. There was a simultaneous invasion of the Aleutians, which was meant to lure the USN north, but thanks to code breakers, the US did not bite. Establishing airbases in the Aleutians was intended to protect the home islands.
I had always heard the Japanese objective at Midway was to lure the remaining American carriers out to battle and destroy them. Which would’ve prevented another Doolittle raid, of course, but also render the US helpless until the huge fleet currently being built would be ready to oppose them sometime in ‘43.
Parshall ruins the old theory that the Aleutians campaign was designed to lure the USN north.