Most people do not think about maritime geography while filling their car.
They think about the price. At least these days they do.
I usually get bored before the tank is full and only fill it three-quarters. Drives my wife nuts.
All of us, however, are being reminded of just how relevant the Strait of Hormuz and the Persian Gulf overall are to our way of life. What was once a sandy piece of nowhere controlled by barbarians is now a sandy stretch of the most geopolitically sensitive, oil-rich strip of land, still controlled by barbarians.
Those barbarians, however, have a lot of military equipment, and a religious vision to blow it all up so that their fake version of Jesus will come back or something.
As I recently explained to the wife and kids, the Persian Gulf is the cajones of modernity.
The global economy, when viewed from glittery shopping centres or hipster holiday locations, looks sprawling and indestructible. Supply chains cross oceans. Energy markets operate across continents. The system is planetary in scale and so seems indestructible.
But geography has a wicked sense of humour. Complex civilisations rely upon one or two key commodities to function, and geography loves to put those commodities in really difficult-to-hold locations.
Civilisations grow outward, connecting distant resources to crowded centres of power. Food moves from fertile regions to cities. Metal travels from mines to workshops. Energy flows from remote fields to industrial economies. Over time, those movements become organised into routes, and those routes often pass through narrow corridors that cannot easily be replaced.
The larger the system becomes, the more it depends on these passages.
History is full of them.
Imperial Rome was able to feed itself thanks to Egypt. It’s why Julius Caesar and Mark Antony both focused on the place. It wasn’t Cleopatra’s saucy charms that took them there. It was grain.
After Augustus annexed the province in 30 BC, Egypt became the most important supplier of grain to the capital. Each year, fleets of merchant ships sailed from Alexandria across the Mediterranean toward Ostia, the harbour that served Rome. Their cargo sustained the annona, the system that distributed grain to hundreds of thousands of citizens.
The Nile provided a predictable annual harvest that became the mainstay of the Roman system of bread and circuses.
The arrangement made logistical sense. Egypt was fertile, productive, and connected to the sea through the Nile. But it also created a peculiar vulnerability. Rome had grown into a city of extraordinary size, perhaps two million inhabitants. A population like that cannot easily feed itself from nearby fields.
If the grain fleets were delayed, the consequences were immediate. Ancient writers describe episodes of unrest when shortages appeared. Bread is political, and the Romans knew it.
Control of Egypt therefore carried strategic weight. During the turbulent Year of the Four Emperors in AD 69, Vespasian strengthened his position by securing Egypt and its grain supply. Whoever held the province possessed a quiet lever over the capital.
Rome’s legions dominated the Mediterranean world. Yet the stability of the city rested on ships sailing from one province.
Empires expand by conquering territory, however they endure by organising supply.
Early modern Spain depended on a different cargo.
Beginning in the sixteenth century enormous quantities of silver flowed from the Americas to Europe. The mines of Potosí in the Andes and the great mining regions of Mexico produced a stream of bullion that financed Spain’s imperial ambitions.
Transporting that wealth required careful organisation. The Spanish crown developed the treasure fleet system, heavily escorted convoys that carried silver across the Atlantic. These voyages linked American mines to European wars.
The system worked remarkably well for long stretches of time. But the dependence it created was unmistakable. Storms could scatter ships. Privateers could capture them. Delays could ripple through imperial finances.
Spain remained the most powerful monarchy in Europe for much of the sixteenth century, yet its treasury waited each year for the arrival of convoys from the New World. Even with rivers of silver flowing inward, the Spanish crown declared bankruptcy several times as war expenses outran the timing of shipments.
When the rivers of gold and silver ceased, so did the glory of Hapsburg Spain.
The relationship between trade routes and power also shaped the history of Han China.
The Silk Road was not a single road but a network of routes connecting China to Central Asia. Through these routes flowed silk, horses, precious goods, and diplomatic exchanges. Control of the western approaches therefore mattered greatly to the Han state.
One geographic feature was particularly important. The Hexi Corridor, a narrow band of territory that connects the Chinese heartland to the deserts and steppe beyond, was the chokepoint for the commodities and luxuries that flowed back and forth to sustain the Han Chinese golden age.
Han emperors invested heavily in securing the region. Garrisons were established, campaigns were launched, and alliances were negotiated with Central Asian peoples. Trade and security moved together.
When the Han dynasty weakened in the second and third centuries, authority over these frontier regions eroded. Caravans became more difficult to protect. The great trading networks that once linked China to distant markets grew less stable.
As the Chinese lost control of the corridor, their standard of living and geopolitical weight diminished. It is only today, with the development of the Belt and Road Initiative, that the Chinese look to be about to regain their geopolitical position.
Across these very different societies a common pattern appears.
Rome depended on grain fleets sailing from Egypt.
Spain depended on silver convoys crossing the Atlantic.
Han China depended on corridors that connected it to the Silk Road.
The details vary but the pattern is the same.
Civilisations grow by linking distant resources to concentrated centres of power. This requires dominating the locals in the regions that strategic commodities are sourced from. This drains the empire’s strength over time.
The modern world runs on oil to an extent that few of us were aware of until now.
The Strait of Hormuz is the chokepoint. The Persian Gulf is where the cheapest, most easily available oil is sourced from, and it has to pass through the Strait to get to refineries and industrial systems mostly in Asia. Billions of people depend upon the economic activity that oil enables.
The Roman grain fleets fed a single city. The silver fleets financed a single empire. Tankers passing through Hormuz sustain industrial economies across the entire planet.
The system looks enormous, but the Iranians are able to take it out by squeezing it at its most vulnerable point.
And they’re squeezing those cajones hard.
