HE didn’t miscalculate, simply warned his government. I don’t think he ever believed victory was possible, and was hoping for a settlement instead.
Not an outlandish concept; Americans forget that while we were slogging our way across the Pacific, and supplying the USSR, Japan and the USSR had a peace treaty that lasted until late 1945.
The movie Gallant Hours was on a few weeks ago. It stared Cagney as Halsey and followed an approximate two month time of his command which included the Yamamoto raid. From what I gather, it was a pretty accurate depiction. According to a part of the story line, Yamamoto decided to do a visit to the forward areas based on a visit Hallsey had made to our forward area which seemed to rally moral.
The Soviet Union did not want to fight a two front war.