The I-400's intended strike role resembled modern submarine-launched land attacks: once a weapon fires, it risks revealing its position, and the defender's security posture tightens. A design submitted in early 1942 could not arrive when Japan most needed strategic surprise. The original plan for eighteen boats made sense only if enough could maintain recurring pressure on the American coast much earlier in the war. Yamamoto's death in 1943 also removed the leading sponsor who might have defended that large construction programme and its original employment concept.
Notable Point · 19:05-21:58
Why timing mattered more than novelty
A covert strike weapon has its greatest value at the opening of a war, before a defender has raised security and organized countermeasures.