My point about the contrasting histories of India and China may have been poorly made.
India has a long history of division. Occasional great empires would rise, but the peak of their power would usually be very short and the area they controlled would quickly fall back into regional and then often local states.
India was one of the most divided areas of the world. Not only by religion, ethnicity and language, but also by caste. Throughout its history the caste system has been elaborating and proliferating. As time goes by, India has become more and more subdivided in this way.
Politically, prior to the British conquest, India was never once completely subdued by a native power or foreign invader. Even today, “India” in its geographic sense is divided among three mutually hostile countries. This is normal for India and is actually much less split up than is normal for its history.
Most critically, prior to the British Raj Indians had never thought of themselves as such. Their self-image was built on their local state, their language, their ethnicity or probably more often their religion or caste. The very idea of “Indian” as a nationality grew out of resistance to British rule.
China, OTOH, has a long history of expansion and assimilation. Initially, “China” was limited to a small portion of the Yellow River plain. Over the millenia this culture spread out in all directions. As it did so, the people already living in the areas it conquered were assimilated and began to think of themselves as Han Chinese. They did indeed become Chinese.
The assimilative nature of Chinese civilization was so powerful that it was able to assimilate groups speaking radically different languages, forming what is the only truly multi-lingual civilization/culture of which I’m aware. They of course shared a written language, but the vast majority were illiterate. Nevertheless they all thought of themselves as Han Chinese.
When Chinese dynasties collapsed into a welter of states, their natural tendency, unlike that of India, was to coalesce back into large regional and then entire national empires.
The parallel to competing ideologies in America society is actually quite interesting. China is historically a melting pot. Other groups get assimilated and become Chinese. India is historically a multi-cultural “salad.” Different groups live alongside each other for centuries without melding.
Parts of Tibet and Manchuria were ruled at various times by empires that incorporated parts of China, and various Chinese empires ruled parts of these “countries.”
Also the history of civilization in the Yellow River of China is almost as old, if indeed not as old, as it is for the Indus River of India.