It's hard to overstate how much of advantage the computers in Bletchley Park gave the allies in WWII. At least bump the Computer Age back one year so you can get D-Day in there.
Bletchley Park did not have general-purpose computers as we understand them. They had special-purpose hardware key-testers - the electromechanical bombe, and the electronic Colossus. Their successor today is a Bitcoin miner.
Although it gets less publicity today, Friedman's cryptanalysis operation in the US did much more number-crunching. Friedman turned cryptanalysis from guessing and testing into a statistical problem.[1] He and his organizations made heavy use of modified IBM tabulators during WWII.[2] Those were much more general purpose machines, somewhat programmable.
It seems to me that “military history” in this case is like a 30-year preview of the Computer Age: maybe I’m just young, but I’d generally put the start of the Computer Age around the time of the invention of FORTRAN and Lisp. To my mind, everything before was a “beta”.
