Dependence on Indochina gives Japan a concentrated supply system that Allied submarines could threaten. Three months is too little time to create a much larger submarine force in the Far East because the boats need a support network as well as crews. A heavy bomber squadron has the same problem because its ground organization must travel with the aircraft. Destroyers have a similar need for bases or depot ships. Cruisers can perform more maintenance aboard because their size provides room for workshops and equipment, which gives them greater independence from forward support.
Notable Point · 18:38-19:44
Why Allied submarines cannot multiply in three months
A larger Allied submarine threat needs bases, tenders, workshops, and support personnel, so three extra months cannot transform the South China Sea force.