Dire straits: How narrow water rules the world
History is not a strait line
The global economy is in dire straits. No, not like the British rock band that defined an era of music videos. Like the narrow bodies of water that connect two larger bodies of water. You could argue that these seemingly insubstantial bodies of water have impacted history in more ways than some of the greatest oceans or seas on the planet. So how is it that the world’s economic wellbeing has been so closely tied to maritime choke points—both today and historically?
Let’s start with the Strait of Hormuz. This 30-mile-wide waterway connects the Persian Gulf and the Gulf of Oman. About 35 million years ago, the Arabian and Eurasian plates collided, collapsing the Tethys Sea between them. The Arabian plate subducted under the Eurasian plate, pushing up the Zagros Mountains in Iran and creating a depression that became the Persian Gulf.
This ancient tectonic activity is also what makes the strait so influential today. For millions of years, the Arabian plate sat below sea level, where it collected the rocks needed to form oil and gas. When the plates collided, these pockets of fossil fuels were pushed under the land we know today as Iraq and Iran. These oil wells are among the largest in the world, and most of the oil they produce passes through the Strait of Hormuz. I’m sure you get what’s coming.
The global economic system runs on oil. The Strait of Hormuz sees over 21 million barrels pass by each day—one fifth of the global supply. Hormuz is the global economy’s most vital—and most vulnerable—maritime choke point. Any disruption to traffic through Hormuz affects nearly every nation and industry, including agriculture, aviation, transportation, shipping, chemical production, manufacturing, and electricity generation, to name a few. Today, as conflict drags on between the US, Israel, Iran, and a host of other regional players, the vulnerability of this strait is why so many things have suddenly become more expensive, less certain, and contentious.
The global economy is strait-up complicated
Hormuz isn’t the only example of how complex trade across narrow waterways has impacted history. As Big History teaches us, increased complexity leads to increased fragility. And in the last decade, the world’s narrow water passages have continued to make this concept painfully clear. In 2021, the Ever Given, a massive container ship, ran aground in the Suez Canal (don’t be literal—canals are basically human-made straits!). For six days, the ship blocked 12% of global maritime trade. It cost the global economy about $400 million per hour.
The Suez Canal moves about 5 million barrels of oil per day. Yes, that’s far less than Hormuz, but not insubstantial. The main difference between the situations in Suez and Hormuz is that there were alternative routes to the Suez Canal. These alternative routes were more expensive and slower, but they didn’t create the total disruption and logjam we see today in Hormuz.
Strait? You’re just a salty river!
Once you remove oil production from the equation, few straits have remained as enduringly relevant as the Turkish Straits—the Bosphorus and Dardanelles. These straits connect the Black Sea to the Mediterranean, linking Russia and Eastern Europe to global shipping. Today, the Turkish Straits see around 4 million barrels of oil a day. Situated between Europe and Asia, between the Black and Aegean Seas, and passing Constantinople/Istanbul, the Turkish Straits have been a crucial choke point throughout history. This narrow strip of water has seen conflicts between Greeks and Persians, Athenians and Spartans, Ottomans and Byzantines, and Alexander’s Diadochi. More recently, it was a key flash point in the Crimean War, World War I, and the Cold War.
In antiquity, the Dardanelles (then called the Hellespoint) was once punished by an angry emperor. On his ill-fated invasion of the Greek Peninsula, Persian emperor Xerxes I needed to get his army across the strait. After the two bridges he built were destroyed in a storm, Xerxes reportedly flew into a rage. Herodotus claims that Xerxes had the strait branded and whipped. As they whipped the strait, his soldiers belittled the unapologetic water:
‘You hateful water, our master lays his judgment on you thus, for you have unjustly punished him even though he’s done you no wrong! Xerxes the king will pass over you, whether you wish it or not! It is fitting that no man offer you sacrifices, for you’re a muddy and salty river!’ In these ways he commanded that the sea be punished and also that the heads be severed from all those who directed the bridging of the Hellespont.1
Xerxes eventually managed to cross the strait by tying together ships. Nonetheless, he lost his war after his navy was destroyed in a battle at the Straits of Salamis. Clearly, you should never insult a strait.
After the Greek and Persian wars, the straits remained critical. The Athenian Empire relied on grain shipments from the Black Sea. After Athens lost control of the Hellespont to Sparta round 405 BCE, the city nearly starved, forcing the once mighty maritime empire to surrender to its rival. Grain shipments through the Turkish Straits remained a key economic factor for the next 2,400 years (more on that in a moment).
Meeting place of all merchants
Until the modern era, the most important strait in the world was probably Malacca. Valuable trade passed through these waters, traveling between China, India, and the spice islands of Southeast Asia and on to the Middle East and Mediterranean. Various states controlled these straits, including the Srivijaya Empire and the Malacca Sultanate. Malay sources claim that Arab merchants named the city Malakat, meaning “meeting place of all merchants.”2 After 1511, the straits were controlled by several European empires, the first of which was the Portuguese.
Few empires have leveraged maritime straits to their advantage better than the Portuguese. During the sixteenth century, the Portuguese empire controlled several key choke points. With a small navy of powerful gunships and the presence of just a few thousand individuals, the Portuguese couldn’t control large populations and territory, but they could apply great pressure at key points. At straits, including Hormuz, Malacca, Palk, and the Mozambique Channel, the Portuguese built fortresses to protect their trade and impose their will on ships passing through.
In 1515, the Portuguese diplomat Tomé Pires served at the Portuguese fort at Malacca. He wrote a book describing the Asian coastline from the Red Sea to China in which he claimed that “Whoever is lord of Malacca has his hand on the throat of Venice.” In the sixteenth century, Venice and Portugal were major rivals, with Venice controlling much of the Silk Roads trade to Europe that arrived in the eastern Mediterranean. By controlling the choke point of Malacca, the Portuguese were able to dictate prices of the goods traveling west from China, as the Venetians had for so long before the Portuguese found a route around the Cape of Good Hope. Eventually, the Dutch and, eventually, the British replaced the Portuguese in Malacca.
Pax Britannica
From 1652 to 1784, the British and Dutch empires fought four wars with each other for control of the seas. In particular, they sought to control the English Channel, a strait that has remained vital to global trade ever since. Today, the English Channel is the busiest waterway in the world by volume of traffic. The British eventually prevailed and displaced Dutch hegemony of the world’s oceans.
In an age when the Sun never set on the British Empire, control of key maritime choke points was essential to British power. British Admiral John Fisher claimed that there were five keys to the world: “The Strait of Dover, the Straits of Gibraltar, the Suez Canal, the Straits of Malacca, the Cape of Good Hope. And every one of these keys we hold.” 4
Unfortunately for the British, there were other critical straits that Admiral Fisher neglected to mention. Nearly 2,400 years after the Spartan blockade of Black Sea wheat brought Athens to its knees, the Ottoman Empire nearly did the same to the British, and it’s a great way to illustrate the fragility of complex systems. In 1914, just seven countries produced 90% of global wheat: Russia, Canada, Argentina, Romania, Australia, India, and the US. A third of the world’s wheat transited the Turkish Straits.
In 1914, after its entry into the First World War, the Ottoman Empire blockaded the Dardanelles, preventing Russian and Romanian wheat from reaching global markets. Wheat prices around the world skyrocketed. Mediterranean nations who relied on these shipments turned to US markets. Concurrent poor harvests and droughts in Australia, South America, and Canada meant that British merchants were competing with new buyers, and the price of American wheat rose from $0.85 to $1.28/bushel in 1914. India, meanwhile, had enjoyed a bountiful harvest, but as global prices surged, wheat flooded out of India, driving up prices for Indian consumers. The government shut down exports to avoid famine.
By 1915, wheat prices had reached $1.63/bushel, and the British Empire was facing a crisis. In response, Winston Churchill (who was First Lord of the Admiralty at the time) devised a plan that proved to be one of the worst failures of the war. The plan hit Turkish mines and fortifications in the disastrous Battle of Gallipoli, where the Allies lost in a deadly battle after drastically underestimating the Turkish forces. Still, the Gallipoli campaign did provide some relief. During the year-long battle, wheat prices stabilized as markets reacted to the possibility of the Dardanelles reopening. One British merchant remarked in March 1915 that “Every shot fired in the Dardanelles is a shot fired into the Chicago wheat pit.”
Fossil-fueled straits
During World War I, Admiral Fisher pushed the British navy to convert from coal to oil. This choice transformed naval warfare and was the single largest driver of the global energy transition from coal to oil. Oil, more than spices, cotton, coal, or any other commodity was now the lifeblood of the global economy. And thanks to the D’Arcy Concession and the discovery of oil in Iran and other Gulf States, around a quarter of global oil since the mid-twentieth century has transited the Strait of Hormuz.
The current crisis between Iran and the US is not the first time the Strait of Hormuz has generated global crisis. Iran in particular has frequently leveraged the closing of the strait in international negotiations. During the Iran-Iraq War (1980–1988), both sides attacked oil ships in the so-called “Tanker War.” In 2012 and 2019, Iran’s threats to close the strait caused oil prices to skyrocket.
Still, the current crisis is different. The International Energy Agency claims that this is the “largest supply disruption in the history of the global oil market.” It has cut the global supply of oil by up to 13 million barrels each day since February. Dozens of nations have declared emergency economic measures in response. And, unlike during previous crises, such as the 1970s oil embargo, this crisis is affecting agricultural fertilizer, jet fuel, and liquefied natural gas.
I have good news and bad news. The good news: Eventually—and certainly—the Strait of Hormuz will cease to be a contested sea lane. Governments will stop fighting over it. The bad news: That won’t happen for another 10 million years. The Musandam Peninsula, which forms the southern edge of the strait, is still being forced under Eurasia. It’s sinking six millimeters each year. Eventually, it will reach the southern coast of Iran, closing the straits. In the meantime, humans will need to learn to stop shooting at each other.
2 https://www.tandfonline.com/doi/full/10.1080/13639811.2024.2373582#abstract
3 By the way, this claim is still literally true, though some pending legislation and a treaty between the UK and Mauritius could make it false for the first time since the eighteenth century.
4 Milan Vego, Maritime Strategy and Sea Control: Theory and Practice (London: Routledge, 2016), p. 188. Quote sourced from The Papers of Admiral Sir John Fisher, Vol. I.
About the author: Bennett Sherry holds a PhD in history from the University of Pittsburgh and has undergraduate teaching experience in world history, human rights, and the Middle East. Bennett writes about refugees and international organizations in the twentieth century and is one of the historians working on the OER Project courses.
Header image: Composite with the Persian Gulf as seen in Google Earth.