Answer:
because of the attacks on pearl harbor and the countless loss of lives that day
Japan<span>: Japan's Yamato dynasty traces its origins back to 660, making it the oldest continuous hereditary monarchy in the world. The 79-year-old Emperor Akihito has reigned since 1989 and is, according to legend, the 125th emperor in his line, though there's some debate as to the exact count of emperors</span>
Because it offers the historian an objective snapshot of the public sentiment of the time, which the cartoonist (should be) distilling for their readers, according to their feelings, for mass appeal. I say objective as it is usually very easy to decipher their subjective viewpoint according to the publication. The value of this is that it is tapping into how the masses 'feel' rather than how subjective facts can be built to form historical opinion. It becomes especially valuable prior to this century, when public sentiment is harder to garner as we were less technologically advanced.
