The argument rests on Yonai's naval identity, personal debts of loyalty among senior officers, and the navy's greater exposure to the realities of fighting the United States. Isoroku Yamamoto is the specific example of an admiral who owed Yonai his life because Yonai had protected him during the coup tensions. The fleet's core would probably remain with an emperor-backed government even if parts of the army rebelled. Britain and the United States would likely avoid direct intervention but could channel food, ammunition, and other supplies toward their preferred side. That combination could make a Yonai victory comparatively swift, although even a short civil war would be violent.
Notable Point · 1:29:13-1:32:31
Why the navy could be decisive in a civil war
Much of the navy would probably support an emperor-backed Yonai government, giving it a major advantage over rebellious army elements.