The heart of geopolitics is understanding how people relate to power. Under what circumstances is power obeyed, when is it ignored (and when can it be ignored and when can it not) and who is allowed to rise to the top.

Key to all that is understanding also where people are placed. Often, that’s the geographic equation of the situation: mountains, deserts, plains, etc. that affect how power is directed. But the human geography is just as important.

And in the twenty-first century, the most important human geography can be found in cities. Here, technology advances. Governments meet. Weapons are designed. Foot soldiers recruited. Economies carry on. If humanity can be equated to a single human body, then cities are the hearts that pump life.

First, the wayback machine and the role of the city in the state

In prehistory, tribes broke into two forms: the nomads, who wandered and lucked upon resources as they could, and the semi-settled farmers and foragers, who would pick spots for long periods of time and use them as locations to store resources, establish shelter and create defensible territories. (Defensible, in those days, from both other tribes as well as animals and nature.)

Both groups developed leadership castes that led the tribe to success or failure. The semi-settled folks, if blessed with a good enough village, would eventually overpopulate: prehistoric farming and resource gathering would invariably be unable to support limitless growth. So leadership would either exile or send forth parts of the village to found a new village elsewhere and replicate the process, thereby keeping the whole tribe from starving to death.

Settlement had its advantages. Building a village created a long-term solution to the shelter problem: once a hut was up, it could last a while while the nomads fecklessly wandered from one cave or natural shelter to another. It allowed storage of food, especially once farming took hold around villages and let people save up for winter. It also demanded organization: once a village hit a certain size, the whole honor system fell by the wayside and required stronger leadership to establish clear rules for everyone.

It is that latter part that lies at the center of the relationship between cities and states: the more complicated the city, the more complicated the state.

As people advanced technologically, cities, and not the countryside, became the center of geopolitical power. To fell your foe meant capturing their capital city, not their farmlands. To rule a kingdom meant to install yourself in the capital’s palace. Meanwhile the countryside sent force resources to support the city dwellers.

Cities were badly outnumbered by the rural folks, but for the most part that didn’t matter. In pre-modern days, farmers were spread out and disorganized. Only if cities mismanaged them to the extreme could enough be motivated to take on a city’s rulers. Cities, on the other hand, were full of men who could be quickly employed as government troops to force recalcitrant farmers to carry out the government’s orders. This wasn’t the same as waging open war: rather, as the center of communication and law, cities saw geopolitical problems long before farmers could and redistributed power to solve them, even if these problems were the country folk themselves.

Which helped create the two totally different human cultures of cities and country

Cities gathered as many resources as they could from the country and refashioned them into instruments of power — minerals for weapons, food for population storage. Government needs led to the invention of writing to keep track of all this and writing then gave way to laws to provide order to the many strangers who kept trying to take advantage of one another. In the space between, cultural forms became more and more advanced as bored city dwellers experimented and explored with the human experience. Religions that might have started in the country became more than just folk tales in the cities, developing into all-encompassing ways of life.

The cities, in turn, brought form to the masses of farmers by creating standardized languages and cultures to enable city-based power. What good, after all, is a law that you have to translate as soon as you go past the city walls?

Country folk picked up what bits of culture they needed and discarded the rest: a key reason why rural dwellers have always seen cities with suspicion, since they brim with rules and practices that make zero sense outside of them.

Cities, meanwhile, became quite good at managing the country, but increasingly found it hard to govern themselves

The ancient cities of Rome, Athens, Babylonia and Xi’an used their superior organizational skills to keep the countryside divided and in check. Rural rebellions were put down or surplus population was sent to war, put to work in the cities or sent off to colonize land further afield. So long as simple technology prevented cities from growing beyond a particular size (with disease sweeping through to cull the herd on a routine basis), cities could and were governed by a handful of autocrats making all the decisions.

There doesn’t appear to be any hard and fast rule as to when a population grows too big for a dictatorship: after all, the smaller Republican Rome gave way to a much more populous Imperial Rome. What matters is that a city has enough people to create a pool of potential revolutionaries: that pool’s necessary size varies by time, culture and technology.

At a certain tipping point, cities become not cauldrons of power but bastions of instability: angry masses storming barricades and so on. In such circumstances, states turn their powers away from the countryside and toward the city streets. Depending on the strength of the state, such urban rebellions are either put down or overwhelm the state’s defenders and install a new regime.

Syria’s modern civil war is emblematic of this whole situation. The initial rebellion began in the cities: the state, however, fired into the crowds, hoping to dispel them. Since then, the rebellion has largely been a war of urban versus rural, with the biggest cities remaining in regime hands while the rebels roam the countryside. Few major cities have ended up in rebel hands: the countryside simply lacks the power to overwhelm the city garrisons minus a few towns.

And while cities have always been the center of power, today they have crowded out the countryside almost totally

European nation states once balanced the countryside with the city or risked ruin: today, major cities dictate national policy, with urban centers like Paris, London and Berlin setting cultural, social and political trends more than they ever have. To change these systems requires victory in said capitals: it was, after all, only with the fall of Berlin that Nazi power finally collapsed. But even democracies play by the same rules: can one imagine a British or French government that lose London’s or Paris’ political districts?

Cities are also the cultural drivers of whole nation states. The outsized influence of Los Angeles and New York City — which combined have perhaps only 25 million people in a nation of 315 million — is clear to anyone who watches globalized TV. The American countryside is the bedrock of American cultural conservatism, which is currently on the losing end of just about every cultural battle of the past few years, from gay marriage to drug laws to now transgender bathroom rights.

While the countryside remains the domain of resources, mechanization has also severely underpopulated it: fewer people than ever, as a ratio of the nation, lived in modern, developed countrysides. Instead, people crowd into cities, interacting with high culture, power politics and the immediate geopolitical needs of their nation states.

This has also transformed how elites behave. Elites are no longer in distant palaces behind high walls: while New York City’s Upper East Side might well seem desolate, the protests in front of Trump Tower are a reminder that the masses are closer than ever. Elites therefore must become more responsive and transparent than ever: they can no longer count on remoteness to shield them. Their neighbors are no longer necessarily elites themselves but random citizens with axes to grind.

And this trend seems to be accelerating rather than dying off

If there is a great next wave of human migration, it seems to be toward cities — especially older, more established ones, as people abandon not just the countryside but the suburban in-between. Once the refuge for the middle class fleeing the cities, today’s young people are moving back into city centers while their elders fill up the space at the edges of civilization. As these elders die off, it’s unlikely their children will move back into their homes: the generational traits of modern millennials indicate they will prefer big, crowded cities, where their geopolitical influence on their elites will be greater.

This means elites that play by old backroom rules will find themselves increasingly on the out while elites that can play the game of both transparency and politics will thrive. Power will be used more efficiently: pet political projects will be harder than ever to carry out. That being said, politics may be more complicated than ever, as urban factions organize and strive for dominance close the centers of power. They have always done so but in the future they may well be bolstered by the ranks much larger than the elites ever expected. Witness now Donald Trump in America, where an insurgent joke of a candidate has outflanked the elite’s best.

Some cities, built on the suburban model, may well experience a twenty-first century much like Detroit: decaying, desolate, empty reminders of a past few want to rebuild. Power instead will shift to urban cores. This will make governing much more complicated, but potentially better if done right. Otherwise, cities may well give way to urban chaos, with endless cycles of revolution and violence as the mode of politics.

This seems unlikely; the developed world has thus far curved toward peace since World War II. But it is hardly out of the cards.

This story first appeared at Geopolitics Made Super, May 11, 2016.