
Vietnamese, like the language of the Cambodians, is Austro-Asiatic. In fact, the whole zone between South Asia and the modern day Vietnam, and south to maritime Southeast Asia, may have been Austro-Asiatic speaking ~4,000 years ago, as upland rice farmers migrated from the hills of southern China, and assimilated indigenous hunter-gatherers.
But the proto-Vietnamese language was eventually strongly shaped by Chinese influence. This includes the emergence of tonogenesis. Genetically, the Vietnamese are also quite distinct, being more shifted toward southern Han Chinese and ethnic Chinese minorities such as Dai. My personal assumption is that this is due to the repeated waves migration out of southern China over the past few thousand years, first by Yue ethnic minorities, and later by Han Chinese proper. Many of these individuals were culturally assimilated as Vietnamese, but they clearly left both their biological and cultural distinctiveness in what was originally an Austro-Asiatic population likely quite similar to the Khmer.
As I have posted elsewhere it is also clear to me that Cambodians have Indian ancestry. Because unlike Malaysia Cambodia has not had any recent migration of South Asians due to colonialism, the most parsimonious explanation is that the legends and myths of Indian migration during the Funan period are broadly correct. There is no other reason for fractions of R1a1a among Cambodian males north of 5%. Depending on how you estimate it, probably about ~10% of the ancestry of modern Cambodians is South Asian (the Indian fraction is easier to calculate because it is so different from the East Asian base).
This is present in a few Vietnamese (Kinh) samples I have seen, but it is at a lower frequency. The reason for this Indian ancestry is that southern Vietnam became Vietnamese only in the last 500 years, and more intensively only in the last 200 years. The Vietnamese with Indian ancestry are almost certainly people who are from the southern part of the country with Khmer, or Cham, heritage.

The second phase is one of conquest. To some extent to an American who is used to seeing the Vietnamese as being catspaws in 20th-century geopolitics, it is painful to read about the drive south of the Vietnamese, and their extermination and assimilation of the earlier peoples and polities. Though they did not use a word such as “Manifest Destiny,” with hindsight it was clear that the Vietnamese were going to push along the coast southward until someone stopped them by force. As it happened, the rise of Vietnam coincided with the decline of Cambodia.

Though never as extreme as Korea, Vietnamese Confucianism during this period was probably more pervasive than it ever became in Japan (where formal Confucianism tended to be the purview of the samurai class during the Tokugawa age). As part and parcel of civilizing Cambodia, making it Vietnamese, the conquerors attempted to do with the Khmer what they had done to their own people. Diminish the role and prominence of institutional religion, in this case, Theravada Buddhism, and educate the populace so that they could begin to produce their own virtuous bureaucrats.


Though the Vietnamese were aware of the cultural differences between themselves and the Khmer, they were not prepared for the task of swallowing a whole civilization distinct from their own.
This brings to mind comments of Victor Liberman, a scholar of mainland Southeast Asia, that Vietnamese Sinic Confucian statecraft was qualitatively different from the “solar polities” to its west. In his book Strange Parallels Southeast Asia in a Global Context, he outlines what he believes to be the features of these societies which allowed them to emerge
In contrast through steps and starts the Vietnamese developed a society which was in many ways a miniature shadow of that of China to the north. Instead of a divinely sanctioned monarchy, Vietnam produced subordinate kings to the emperor of China or in some cases a ruler who declared he was an emperor himself. Their rule was sanctioned not by gods or priests, but impersonal Heaven and its mandate.
Whereas other Southeast Asian monarchs had court brahmins, bhikkhus, and later in the Malayan world ulema, the Vietnamese monarchs often put away the Buddhist monks and priests and hid any religious devotion from public view. On the Chinese model, the Vietnamese drove religion away as a helpmate, and subordinated religious impulse as ancillary to state functions and transformed it primarily to something that was a matter of popular enthusiasm and private devotion. Like the Chinese, the Vietnamese polity aimed to recruit and produce a large and broad class of virtuous administrators, many drawn from the agricultural populace itself to main social order and proper state function.
Liberman observes that the Chinese model necessarily requires greater coordination, concentration, and mobilization. Additionally, there naturally develops a cultural chasm between the simple peasant, and the educated bureaucrat, in such a society. In contrast in solar polities, the king and high nobility may be distant from the people as symbols, but the vast mass of peasants and clerics interact and engage on a popular level. Religious truths and ideals often can propagate on a dimension closer to the masses than the culture of the Confucian literati. While efficient and constitutive mobilization of the resources of solar polities is low at any given time, mass enthusiasm may be easy to trigger in punctuated bursts of activity around charismatic figures and exigent circumstances.

Their rule was sanctioned not by gods or priests, but impersonal Heaven and its mandate.
Tengrism as pre-modern Asian Deism?
Okay so resolute Sinicization traveled south along the littoral. How’s my {posteriorly-derived} hypothesis looking: that lowland rice paddy-farmers have nowhere to run, and so of necessity become culturally especially stoic in accommodating to entrenched rentier-bureaucratic regimes?
Ben Kiernan’s “Viet Nam” received a lot of criticism regarding it’s Early History section, in particular the Yue origin hypothesis and claim that Vietnamese is Austro-Asiastic. Thorough explanations from a South-East Asia specialist ( https://leminhkhai.wordpress.com/tag/ben-kiernan/ ), and Prof. Kiernan’s insubstantial response, give me pause. This wouldn’t reject the main claim you’re making, and in fact might streamline the narrative of culture clash.
One clarification, the “steps and starts” towards imitating Chinese rule were definitely not monotonic. I don’t think you’d say so either, but one of the benefits of Christopher Goscha’s “Vietnam: A New History,” is the sense of contingency stretching back centuries, even prior to French colonization. If I understand ‘solar polities’ correctly, there were periods of Vietnamese history closer to such an arrangement, perhaps the Tay Son dynasty is an example.
Tengrism as pre-modern Asian Deism?
i guess there’s an argument whether ‘shangdi’ was a personal sky god before it was replaced by ‘tien.’ but i think you are correct to call heaven reverence as depersonalized tengrism….
I assume that modern Vietnamese are mostly descended from the Yue immigrants that fled to the South when Han invaded from the north.
By the way,is the Malay population from Singapore, Malaysia or Indonesia?
To calculate Austro asiatic ancestry of Vietnamese, why don’t we use Dai as one of the source populations?