The video separates high-level imperial defence policy from the doctrine that shaped how Japan planned to fight. Policy defined the objectives and reference points, while doctrine translated them into operations and could in turn reshape later policy. Qualitatively superior ships were intended as both deterrents and conflict-management tools rather than merely prestigious surprises. By making an enemy concentrate, they could create a force that was easier to locate and predict and give Japan a chance to bring its own smaller fleet to bear at a chosen point.
Notable Point · 56:10-1:03:04
Defence policy, doctrine, and qualitative deterrence
Imperial defence policy set broad objectives, while doctrine translated them into a qualitative force intended to deter or channel a stronger enemy's advance.