About half a decade ago Steven Pinker wrote The Better Angels of Our Nature: Why Violence Has Declined. There were many criticisms of the book, but on the whole, I think it pushes forward an argument that is a reasonable description of reality: descriptively, violence has declined over the Holocene.
Why? Carl von Clausewitz asserted “war is a continuation of politics by other means.” I think this gets at an important aspect of the “modern way of war”, and the instrumental use of state and social violence: they exist to reinforce a particular social order. And order tends to go along with peace.
I do not think Clausewitz would have correctly described the world 10,000 years ago. In War before Civilization, the author describes a world of great brutality during the early Neolithic. Peter Turchin has criticized Pinker on these grounds, arguing that violence peaked during the early Holocene, during the transition from a world of hunters and gatherers, to a world of farmers. During the Neolithic, war is often best understood not as diplomacy, but pure eliminationist competition. Animal conflict between rival troupes.
Neolithic farmers, who probably had tribal confederacies, engaged in violence against hunter-gatherers. But except for the more dense societies of the coastal fringes, on the whole, the relationship was probably similar to that between European settlers and Australian Aboriginals: they perceived the indigenous European Mesolithic people as vermin or pests, not as other societies which could be bargained with, or absorbed (though the latter did occur). This probably explains the relatively long period of genetic segregation, as there were strong barriers between mixing between the two populations.
When Genghis Khan conquered northern China he wanted to turn it into pastureland. This would mean a famine to remove the human population of the region. His Khitai advisor, Yelu Chucai, who was stepped in Confucian learning, argued that taxation of the native population would be much more profitable than the Mongols and their allies engaging in primary production through pastoralism. The key to preventing genocide was convincing warlike elites that rents were easier and more profitable than acquiring more land which one had to toil oneself. That is, acquire people, not just land.
I write this in the context of trying to understand the genetic history of India. Why is it that Indo-Aryans contribute at least ~15% of the ancestry on the Gangetic plain, while the later Turco-Muslims contribute almost none? The answer here ventures into ideologically fraught territory because many Hindus take the word of Muslim chroniclers at their word that the predations upon the local population were marked by great brutality and killing.
The northwestern fringe of southern Indian was quite populous during the Indus Valley Civilization period. It was far larger in territory than Mesopotamia or Egypt. In contrast, the Eurasian heartland was always thinly populated. Then, and now. The number of Sintashta descended Indo-Aryans was originally small. It was always reasonable to suppose that their demographic impact was very small. Perhaps like that of the Magyars in Hungary. Ten years ago when the first evidence emerged that India was reshaped by Holocene admixtures I simply refused to believe it at first due to the demographic heft of the region.
So what happened? I think we need to understand that it is likely the early Sintashta warriors did not have Yelu Chucai whispering in their ears. They were horse-warriors par excellence, while the Eurasian oikoumene was relatively underdeveloped compared to what it would be later. There is evidence from Europe that early farming societies underwent massive demographic collapse due to endogenous forces (and perhaps exogenous climate shocks). There is no reason this could not be true elsewhere. Second, aside from the cultural toolkit of farming practices being underdeveloped, ideological justifications for social cohesion were primitive.
When the original Indo-Aryans arrived as agro-pastoralists into a semi-barbarized post-Indus Valley village society I believe they saw pastureland for their cattle and horses! Though some sort of priesthood probably survived, and transmuted into Brahmins (who assimilated many Indo-Aryan priests and shamans), there were no learned advisors handing out ancient traditions of yore. The Indo-Aryans saw an animal battle for resources, and despite their small numbers they “squeezed” the local peasantry (the mtDNA indicates very few Indo-Aryan females, so these were muarading males). This was not an organized ideological genocide, it was simply niche displacement.
In contrast, 2,000 years later when the White Huns arrived from Central Asia, they established themselves as the warrior elite of an already organically elaborated society, with a clear and distinct ideology of self, and local sub-elites which were in place to extract rents from the populace. The Indo-Aryans were more like the Dark Age Greeks, with Odysseus, a “king” still doing some of his own farming and shepherding.
The Turco-Muslims were different in that they had another alternative ideology. They were not uncooked barbarians, they had already been cooked by Islam. They were not absorbed into India because they maintained connections with Iran and Turan, and were part of the broader Dar-ul-Islam. They were in India, but not of India. But, the institutional structures of India were useful for the purposes of extracting rents. India was rich, which for most of history meant rich in people.
The Turco-Muslims came out of a milieu where they were originally slave soldiers of Iranian rulers who lived richly in sumptuous cities. Eventually, they invariably overthrew their masters and moved into the palaces themselves. Unlike the Mongols or their own ancestors, these were not people who had just come out of the tents. They did not have to be educated in the fact that maintaining the mechanisms of the old order would be more profitable than creating from anew.
All this is relevant because some people, Muslim and Hindus, assert that the Turco-Muslims engaged in massive killings and persecutions. The Turco-Muslims themselves claimed to have engaged in incredible violence against the unbelievers, styling themselves ghazis, warriors for the faith. Modern South Asian Muslims implicitly agree with the decimation when they assert that their ancestors were West and Central Asian. Both these contentions are false. The Turco-Muslims, like the Teutonic Knights and Sword Brothers in the Baltic, were proximately motivated by a desire for wealth and leisure. This is clear because the same people spread west out of the fringes of Khorasan, taking over Iranian and Arab polities one after the other through violence. But in the westward movement, there was no religious rationale given, because the Turks were Muslim, and those whom they conquered were mostly Muslim (though the Seljuqs presented themselves as protectors of Sunni Islam, overthrowing the Shia Buywids).
Obviously, this was not the case in India. An idealistic rationale presented itself to mask their avaricious behavior, and they promoted that rationale.
Second, genetically the data is clear that very little ancestry in South Asian Muslims is exogenous. Almost all the ancestors of South Asian Muslims were residents of South Asia 1,000 years ago. Many of the upper-class Muslims who claim West Asian ancestry actually descend from upper-caste Hindus. This is clear when you look at the true Y chromosomal lineages of Syeds, those who claim paternal descent from the lineage of Muhammad’s clan.
From the perspective of Hindus, 30% of the people of the Indian subcontinent are now Muslims. This is a traumatic fact for them. Additionally, between 1200 and 1750 AD Muslims were dominant across most of the subcontinent, and engaged in a project of cultural imperialism and hegemony which left psychic scars on the Indian elites, and physical scars on the architectural landscape. To be entirely frank, a project of coercive, brutal, and violent, conversion to Islam by Turks is in some ways more reassuring to many Indian elites than the fact that there was a softness to the support for native Indian religious views in many parts of the subcontinent. As it is, Hinduism remained the overwhelming religion in the heart of Turco-Muslim power in the upper reaches of the Gangetic plain, with Islam made particular headway in the margins and fringes of South Asia.
The bigger picture here is that human societies and cultural systems evolve, and become more robust. The gap between the Han and Suit-Tang was more than 300 years. The “handoff” between the Ming and Ching (Manchus) was nearly immediate. The Chinese ideological system of rule became more efficient, more effective, over time. The ideological system of domination and control was perfected. The Manchus placed themselves on top of machinery that they inherited roughly intact from the Ming. This is not to say that they could not employ genocidal brutality. The Oirat Mongols were the last great nomadic polity. To “solve” this problem the Manchus in the 18th century engaged in a program of extermination against the Oirat led Dzhungar confederacy. By some estimates, 90% of the Dzhungars died, whether through direct slaughter, or, more often, starvation.
Of course, the Manchus were not ideologically oriented toward genocide. It was simply an instrument. Nor do I believe that the peoples of the Neolithic and Bronze Age were ideologically oriented toward genocide. The question would not make any sense. Rather, the extermination of other groups was simply an instrument of existence in their lives. They died. Or their enemies died.
The interests of the German peasant-warrior flooding into the Roman territories were to drive off the local peasants and their landlords. The interests of the tribal elite was to increase the number of people whom they ruled and could extract rents from, as well as maintaining the position of some of the older elites as service nobilities and candidates for positions within the Church. Similarly, the English settlers in the New World consistently behaved in a more brutal manner toward the native peoples and attempted to push into the interior far more vigorously, than anything the British crown wished to countenance. In an economic and political world of stability, the British crown would do better, but the interests of the American colonists was toward more aggressive dynamism.
It was the emergence of complex multiethnic imperial systems, along with class stratification and divergence of interests, that the reflex toward genocide declined. A “flat” world is a violent world.