Peacetime doctrine shaped an awkward fleet

Did Japanese construction match its doctrine, or did it lose sight of why it was building ships?

It reflected several doctrines, especially a peacetime deterrent logic, but did not always create the most sensible wartime force.

Ships can serve several doctrines without being equally suitable for all of them. Japanese construction mixed a peacetime deterrent logic with several wartime concepts, producing individually formidable ships that did not always form the most useful fleet. For an attrition strategy against an already damaged American advance, matching or surpassing every rival ship's individual capability mattered less than building enough balanced forces to exploit the intended battle. Even submarine range reflected the expectation of fighting nearer Japan rather than crossing the whole Pacific like American boats. Procurement should therefore be judged against the campaign a navy expects to fight, not the isolated specifications of its most impressive hulls.