The counterfactual puts all eighteen planned boats into service by June 1941 while foreign intelligence still knows little about their capabilities. Using them around the Pearl Harbor period might have made Japan's long-term position even more complicated, but the wider reaction remains an open question. Long-range Japanese raids could also have altered contemporary judgments of German attempts to operate against the American Eastern Seaboard. The I-400 belonged to a wider field of capable submarines and designers, though this class stayed unusually close to its original concept.
Notable Point · 32:44-34:47
What if eighteen I-400s were ready in 1941?
The counterfactual asks how eighteen operational but poorly understood I-400s would have changed the opening of the Pacific War and perceptions of long-range submarine attacks.