Turkish straits
Based on Wikipedia: Turkish straits
Every major war in the last two centuries has, at some point, come down to a question about two narrow channels of water in northwestern Turkey. Control these straits, and you control the fate of empires.
The Turkish Straits are deceptively simple on a map. Two waterways—the Bosphorus in the north and the Dardanelles in the south—connected by the small Sea of Marmara in between. Together, they form the only passage between the Black Sea and the Mediterranean. Ships carrying Russian oil, Ukrainian grain, or Romanian steel have no other way to reach the open ocean. This geographic accident has shaped world history for three thousand years.
The Geometry of Power
The Bosphorus is astonishingly narrow. At its tightest point, it measures just seven hundred meters across—less than half a mile. You could swim it in twenty minutes. The ancient Persians simply built a bridge of boats and marched their armies across. Modern Istanbul straddles this waterway, making it the only major city in the world that sits on two continents simultaneously.
Three suspension bridges now span the Bosphorus, along with two underwater tunnels—one for trains, one for cars. The city's European and Asian halves pulse with commuters crossing continental boundaries as casually as New Yorkers cross the East River.
The Dardanelles, sixty-eight kilometers to the southwest, is longer but similarly constrained. At its narrowest, the strait measures barely a kilometer wide. The ancient Greeks called it the Hellespont, and it features in some of the oldest stories in Western literature. In the Iliad, Greek ships sailed through here to besiege Troy, which sat on the Asian shore. The mythological hero Leander supposedly swam across each night to visit his lover Hero on the opposite bank—a swim that the Romantic poet Lord Byron famously recreated in 1810, nearly drowning in the attempt.
Why Geography Becomes Destiny
To understand why these straits matter, you need to understand what lies beyond them. The Black Sea is essentially a lake with a single outlet. Russia's entire southern coastline faces this enclosed sea. So does Ukraine's. So does Georgia's, Romania's, Bulgaria's, and Turkey's northern shore.
For centuries, Russia has dreamed of warm-water ports—harbors that don't freeze in winter, allowing year-round naval operations and trade. The Black Sea ports of Sevastopol and Odessa seem to offer this. But there's a catch. Every ship leaving these ports must pass through the Turkish Straits to reach the Mediterranean, then through Gibraltar to reach the Atlantic, or through the Suez Canal to reach the Indian Ocean.
Turkey, by an accident of geography, holds the keys to Russia's maritime ambitions. This has made the straits a flashpoint in nearly every major European conflict since the eighteenth century.
The Straits Question
During the long decline of the Ottoman Empire—the "sick man of Europe," as Tsar Nicholas I memorably called it—European powers engaged in constant diplomatic maneuvering over what would happen to these waterways when the empire finally collapsed. Historians call this "the Straits Question," and it consumed foreign ministries from London to St. Petersburg for nearly a century.
The fundamental tension was straightforward. Russia wanted guaranteed access for its warships. Britain wanted to keep Russian warships bottled up in the Black Sea, away from the Mediterranean, the Suez Canal, and the sea routes to India. France, Austria, and Prussia all had their own interests in preventing any single power from dominating this chokepoint.
In 1841, the major European powers signed the London Straits Convention, which established what diplomats called the "ancient rule"—the straits would be closed to all warships in peacetime, except those belonging to the Ottoman Sultan's allies during wartime. This compromise satisfied no one completely but prevented immediate conflict.
The arrangement lasted, with modifications, until World War One changed everything.
Gallipoli: The Straits as Battlefield
By 1915, the Ottoman Empire had entered the war on Germany's side, closing the straits to Allied shipping. This was catastrophic for Russia. The empire's only year-round ice-free ports were now useless for receiving supplies from its French and British allies.
Winston Churchill, then First Lord of the Admiralty, conceived an audacious plan. The Royal Navy would force the Dardanelles, sail into the Sea of Marmara, threaten Constantinople, and knock the Ottoman Empire out of the war. With the straits open, supplies could flow to Russia, shortening the war by years.
It didn't work.
In February and March 1915, British and French warships bombarded the Ottoman forts guarding the Dardanelles. The Ottomans had sown the strait with mines. Several Allied ships struck them and sank. The naval assault was abandoned.
What followed was worse. In April 1915, British, Australian, New Zealand, and French troops landed on the Gallipoli Peninsula, the European shore of the Dardanelles. They expected to sweep aside the Ottoman defenders and march overland to the straits. Instead, they found themselves pinned down on narrow beaches, unable to advance, subjected to constant artillery and rifle fire from the heights above.
The campaign dragged on for eight months. Nearly half a million Allied soldiers were killed, wounded, or fell ill. Ottoman casualties were comparable. The beaches of Gallipoli became synonymous with military futility—heroism squandered in a misconceived operation.
For Australia and New Zealand, Gallipoli holds a significance similar to what Gettysburg holds for Americans. The Australian and New Zealand Army Corps, the ANZACs, suffered devastating losses. April 25th, the anniversary of the initial landing, is still commemorated as ANZAC Day in both countries—a national day of remembrance for all those who have served in war.
Secret Agreements and Broken Promises
Even as men died on the Gallipoli beaches, diplomats were dividing the spoils of a victory that hadn't happened yet.
In March and April 1915, Britain and France made Russia an extraordinary promise. If the Allies won the war, Russia would receive Constantinople and control of both straits. After centuries of being locked in the Black Sea, Russia would finally dominate the gateway to the Mediterranean.
The Russian Revolution of 1917 made this promise irrelevant. The Bolsheviks, who seized power in November, had no interest in the territorial ambitions of the Tsars. They published the secret agreements, embarrassing Britain and France, and withdrew from the war entirely.
The straits remained Turkish.
The Montreux Convention: The Rules That Still Apply
In 1936, Turkey negotiated a new international agreement governing the straits. The Montreux Convention Regarding the Regime of the Straits remains in force today, nearly ninety years later. Its provisions are surprisingly detailed and have shaped every crisis in the region since.
The core principle is that civilian vessels of all nations have the right of free passage through the straits in peacetime. Commercial shipping flows through without Turkish interference—a crucial guarantee for the global economy.
Warships are another matter entirely. The convention distinguishes between "Black Sea powers" (countries with coastlines on that sea) and everyone else. Black Sea powers can send warships through the straits, but must notify Turkey in advance. Non-Black Sea powers face strict limits: their warships can enter the Black Sea, but only in limited numbers, and they cannot stay longer than twenty-one days.
These provisions have shaped military strategy for decades. During the Cold War, they prevented the United States from maintaining a permanent naval presence in the Black Sea. More recently, they've complicated Western responses to Russian actions in Ukraine.
Modern Tensions
The straits remain as strategically vital today as they were a century ago. Russia still depends on them for access to the Mediterranean. Turkey, as the gatekeeper, wields enormous leverage—though the Montreux Convention limits how freely Ankara can use it.
When Russia invaded Ukraine in 2022, questions immediately arose about the straits. Could Turkey close them to Russian warships? The answer was complicated. Under Montreux, Turkey can restrict military transit if it considers itself threatened by war, but the convention's provisions are ambiguous about wars in which Turkey is not directly involved.
Turkey has walked a careful line, restricting some Russian naval movements while maintaining the convention's framework. The straits remain open to civilian traffic, including the tankers that carry Russian oil to world markets—the "shadow fleet" referenced in the Substack article that prompted this essay.
The Environmental Cost
Every year, approximately fifty thousand ships transit the Turkish Straits. They carry oil, grain, coal, manufactured goods, and raw materials. They also carry risk.
The Bosphorus, in particular, is treacherous. The channel is narrow, winding, and subject to strong currents. Large tankers have limited room to maneuver. Collisions and groundings occur with disturbing regularity. An oil spill in the Bosphorus would devastate Istanbul's coastline and potentially the entire Sea of Marmara.
The straits also host populations of bottlenose dolphins and harbor porpoises—species found nowhere else on Earth. Increasing maritime traffic, underwater noise pollution, and the constant risk of spills threaten these endemic populations. The same geography that makes the straits strategically vital makes them ecologically fragile.
Crossing Continents
Perhaps the most remarkable thing about the Turkish Straits is how casually people cross them every day. Istanbul's residents commute between Europe and Asia by ferry, by car through tunnels, by train through the Marmaray, or by foot across the suspension bridges. Children grow up hopping between continents to visit friends or attend school.
The newest crossing, the Çanakkale 1915 Bridge over the Dardanelles, opened in March 2022. It's the first bridge to span that strait in human history. The timing was deliberate—the bridge opened on the anniversary of the Ottoman naval victory over the Allied fleet in 1915, a date of national pride in Turkey.
These bridges and tunnels represent a kind of answer to the Straits Question that nineteenth-century diplomats never imagined. The straits still divide continents and connect seas. They still matter for global shipping and great-power politics. But they're also just part of daily life for fifteen million people who happen to live in a city that spans the meeting point of two worlds.
Geography may be destiny, but people still find ways to bridge it.