Historical migration patterns also show us that, until a few hundred years ago, almost all of the large empires and kingdoms did not suffer from over-population but, rather, under-population. Apart from agricultural lands near large, navigable rivers, most of the hinterlands and the periphery of even very populous civilisations, like India and China, were largely unpopulated until a few thousand years ago.
There were so few people to support large state systems that the elites of these political systems worried more about their own population emigrating away, than foreign people coming in. In fact, the elites often welcomed energetic young people from beyond borderlands to settle within the empires -- the larger the population, the bigger the tax base.
Large empires, by virtue of their wealth concentration and stable centres of state power, have historically always attracted migration from people beyond the borders. But the very inequality of wealth and development between empire and its periphery eventually causes the downfall of the centre and diffusion of wealth across geographical expanses.
Peter Heather, a British historian, has written several books developing a model of fall of empires from political and economic causes. His books, particularly, focus on the fall of the Roman Empire at the hands of Germanic tribes in the middle of first millennium AD -- the classic case of empires and barbarians in history.
According to Heather, an empire comes into being when a particular region enjoys a comparative advantage in development of a political, economic system that enables the region’s sustained domination of the relatively underdeveloped surrounding areas. But expanding empires eventually collide with another, similarly powerful, political entity, with which it engages in prolonged confrontation.
For the Roman Empire, it was the Sassanid Empire of Persia that provided a military rivalry that lasted centuries. The prolonged warfare forced expansion of state bureaucracy and demanded expansion of tax revenue. Meanwhile, gradual diffusion of better production technology, from the core of the empire to the lands beyond the border, meant that the formerly “barbarian” lands became more productive. Economic growth in the periphery supported population growth which, in turn, facilitated growth of powerful elites and political consolidation.
This gradual development eroded the relative advantage of the empire to its periphery. When the new peripheral political units faced pressure from “barbarians” beyond periphery, for the Germanic tribes, it was the Huns from East European plains -- they encroached upon the empire both for safety and the riches. The elites of the empire did not always resist the encroaching tribes, they even welcomed some of them for the increase in population, tax base, and addition to military power. But, gradually, encroachment from the periphery overwhelmed the empire and the political order was overturned.
From his study of The Fall of Roman Empire, Peter Heather proposes a Third Law of Empires: Every imperial rise generates an opposite and equal reaction among its originally dominated neighbours, which will eventually culminate in its own demise. According him, the net effect of the rise and fall of empires, over a long time, is growth, disappearance, and re-growth of inequality elsewhere.
Peter Heather’s theory of empires closely follows Ibn Khaldun’s theory of difference between community cohesion in the empire centre and barbarian periphery -- it also somewhat follows Gibbon’s theory on the fall of the Roman Empire.
But there is a vital difference: Unlike Khaldun and Gibbon, Heather does not believe that the core of the empire was declining, either in economic vitality or social cohesion. In fact, he shows that, right until the fall of the empire in the fifth century, Roman society and economy were as vigorous as ever. It was the wealth of the empire that mainly attracted Germanic tribes, not the opportunity for decadence.
In the modern era, three centuries of relative advantage in economic and political system helped Europe and the West enjoy an economic boom that created a “great divergence” with the rest of the world. The west used this economic disparity to maintain global empires and client states. But, as the economic systems, production technology, and political orders diffused all over the world, the relative advantage diminished and many parts of the world are catching up with the west in the “great convergence.”
But it does not mean that the West is declining in economy and society in absolute terms. Its societies and economies remain attractive to most people living beyond. When faced with violent political instability at home countries, most of the rich and educated people beyond the periphery still prefer the West as the destination for relocation. The elites in the West face an irresolvable dilemma. They need supply of skilled and youthful infusion of cheaper workforce to keep their economy humming, but the ensuing demographic change creates social and cultural tensions that threaten to upset the political order in the destination countries.
Today, Germany is rightfully praised for it opening its doors to Syrian refugees fleeing from the horrors of war that is mostly the handiwork of Western powers and Syria’s powerful neighbours. But some cynical observers also note that hundreds of thousands educated, middle-class Syrians, who are capable of financing the long underground trek to the West, are probably a boon rather than a burden to Germany, with its declining population but highly productive economy.
Just as Germans laud the European Monetary Union in terms of European unity, while under-playing how the EMU benefits the German economy disproportionately, the Germans also managed to find moral tones of humanity and solidarity about welcoming refugees while understating the benefits to the economy.
But many countries in Europe, whose economies are not as healthy and who depend upon economic opportunities provided by the integration with German economy, are rightfully apprehensive at the arrival of so many new people from different cultures at the heart of Europe.
In history, sustained migration has nearly always resulted in political change, and political change is always pregnant with the possibility of violence. The modern liberal democratic system, which originated in the West, will be sorely tested by an inevitable demographic change. The US, which went through several waves of big demographic changes during its 200 years of history, seems to be more robustly capable of coping with change while maintaining political order.
Lastly, I couldn’t resist drawing a fanciful comparison between the macro-historical patterns and an ongoing change in the economic and political elite of Bangladesh. The landed gentry who have dominated society in Bangladesh since 1947, also dominated economy and politics since 1971. The class remained closely-knit across political divides and used their relative advantage to perpetrate dominance over the rest of society, in ways that were very thinly disguised.
But the growth of economy and state meant that the personalised and particularistic political order they helped develop could not stop economic and political power from diffusing to a new class of more vigorous and risk-taking entrepreneurs of power who come from more plebian origins. In the more unconstrained and unstructured social order that democratic politics unleashed since the 1990s, it was the more adventurous power entrepreneurs who thrived and the relative power of the old elites diminished.
Today, the former elites are finding themselves more and more out of place in Bangladesh’s rough-and-tumble economy and society. Many of the old elites are resigned to their fates and they are de-camping to the genteel pastures of the West to meet oblivion in peaceful comfort.
Political leaders in Bangladesh, who have recognised this elite transition and used it to their advantage, are thriving, while leaders who are stuck to the old order watch helplessly as power slips away from their fists like fine sand. And like how sand piles in a windswept dune, economic and political inequalities are continuously diminished and shored up in the large canvas of history.