The counterfactual uses I-400-scale submarines as minelayers rather than aircraft carriers. They could place mines outside San Francisco, the Panama Canal, and other harbors at the opening of war, then withdraw before defenders arrived. Repeated minefields would demand persistent sweeping and coastal protection while threatening new warships near home ports. The psychological effect could matter as much as the losses, because visible failures to secure the American coast might weaken confidence and buy Japan time. This is a proposed alternative strategy, not a claim about what Japan actually implemented.
Notable Point · 2:01:03-2:05:23
Submarine minelaying as strategic disruption
A hypothetical Japanese force of long-range minelaying submarines shows how mines near American ports and the Panama Canal could impose delay, losses, and psychological pressure.