An extremely common AH cliché/mistake which has been known to aggravate Flocculencio, among others, on occasion.
In essence, this error is in assuming that Japan's degree of global power in the twentieth century magically extends backward through time, when in fact until the 1850s Japan was an isolated country lacking the capabilities to accomplish this or project power on even a regional scale.
The most common sign of this was when Japan controls the East Indies, particularly when there's also a united India sitting there doing nothing to protect its cultural satellites.
Over the years, this cliché has mostly fallen into disuse in AH.com proper.