Britain's early-war convoy system provides a more useful comparison in this assessment than its mature wartime escort force. Britain had already developed and ordered Flower-class corvettes and possessed the infrastructure to increase output. German submarine numbers were initially limited, allowing British escort strength to grow alongside the threat. Hunt-class escort destroyers and converted V and W-class destroyers then added further capacity. Japan faced the increasingly capable American submarine force with escort numbers and some equipment closer to an early-war level. The criticism concerns inadequate timing and scale while still recognising the value of the escorts that existed.
Notable Point · 23:04-24:46
Comparing Japan with Britain's early-war escort position
The proposed comparison places Japan's limited escorts nearer Britain's 1939-40 position, while American submarines had reached a much higher level of capability.