The proposed divergence removes the earthquake damage that took Amagi out of Japan's carrier-conversion program. Japan would therefore receive Amagi and Akagi as carriers instead of the historical Akagi and Kaga pairing. Both ships and the treaty framework already exist, so the change remains tightly bounded. The writer then has to trace how the different pair affects Japanese carrier development and later choices. A single external event can redirect a navy's force structure without requiring the treaty system to disappear.
Notable Point · 4:27-5:21
If the Great Kanto earthquake had not doomed Amagi
One example asks how Japanese carrier development changes if earthquake damage does not remove Amagi and Japan completes Amagi alongside Akagi.