Root Canal

At heart just a glorified ditch, a waterlogged trough, a canal is no big thing. Except when it is a very big thing, indeed. Irrigation canals greened Mesopotamia and midwifed the first great civilizations; state-dug canals were the early arteries of England’s Industrial Revolution. The Erie Canal transformed the United States into something much greater than a seaboard trader, while the Kiel Canal drove Germany’s delusions of challenging Britain’s naval supremacy. The Grand Canal helped unify China, while the Suez and Panama canals chopped enormous landmasses in half and redrew both shipping routes and imperial ambitions over the last century and a half.

That set us to wondering: Of all the great canals that have ever been dug, which was the most important? Which canal, that is, has had the most outsized role in world history, by fueling trade, war, or empire?

Foreign Policy asked a slate of experts — historians, archeologists, naval strategists — to weigh in and make the case for what they think is the most important ditch ever dug.

Ian Morris, professor of classics, history, and archaeology at Stanford University, and author of Why the West Rules — For Now and War! What is it Good For?:

My initial reaction was, “Of course, it’s the Grand Canal,” but as I read through your list of examples, I kept thinking, “Oh yes, it’s this one too.” So this is not easy.

That said, I think my vote still goes to the Grand Canal. By linking the Yangtze and Yellow river basins in the seventh century, it plugged the expanding rice frontier of the south into the booming population and political centers in the north. I like to think of the Grand Canal as a kind of man-made Mediterranean, giving China the same kind of cheap transport that the Mediterranean had given Rome, with comparable results. Tang dynasty China would still have been the greatest power on Earth if it hadn’t had the canal, but it was the canal that made it one of the great civilizations of all time, paying for the golden age of Chinese poetry as well as for armies that marched as far as India and Kyrgyzstan and for financiers who created the world’s first paper currency.

It’s certainly true that the economic booms fueled by the Erie, Suez, and Panama canals were bigger still, but I think one big difference between modern canals and pre-modern ones is that the internal combustion engine and jet aircraft have now given us alternatives to shipping for moving things around.

James Holmes, professor of strategy at the U.S. Naval War College and co-author of Red Star Over the Pacific:

You would think the Panama Canal is the world’s most consequential artificial waterway. In 1898, the Pacific-based battleship Oregon had to circumnavigate South America to get into the Caribbean fight against Spain. Decades later, Yale University geopolitics guru Nicholas Spykman wrote that the opening of the canal in effect lifted the United States up and swiveled its geopolitical gaze 90 degrees southward.

Now it looked to the Caribbean Sea and Gulf of Mexico, its conduit not just to the North American West Coast but also to Asia. The U.S. Navy could shift ships from side to side, concentrating superior force in the Atlantic or the Pacific as circumstances warranted. In short, the Panama Canal made American maritime supremacy possible, along with American custodianship over the system of maritime trade and commerce. That’s a big deal.

Nevertheless, I would give the Suez Canal the nod. Digging it did much the same for British sea power as Panama later did for the United States. It granted the Royal Navy ready access to the Indian Ocean, making possible a liberal empire presided over by an unrivaled fleet. How crucial Suez was to Atlantic powers’ endeavors in Asia became clear in 1904 and 1905. That’s when Japan’s ally, Great Britain, closed the canal to the Russian Navy — and in turn compelled the Russian Baltic Fleet to undertake an epic 20,000-mile voyage around the Cape of Good Hope, through the Indian Ocean and South China Sea, and up through the East China and Yellow seas just to meet Japanese Adm. Togo’s tanned, rested, and ready Combined Fleet at Tsushima Strait. The result was predictable: a debacle of the first order.

But there’s another reason to rank Suez ahead of Panama. Had the Suez Canal never been dug, the combined Mediterranean and Black seas would verge on being an inland sea, accessible only through the Strait of Gibraltar. Close Gibraltar, and you bisect French and Spanish naval and merchant endeavors between the Atlantic and Mediterranean coasts. You confine great powers like Italy and Turkey to a dead sea. You create a closed system that constricts seaborne commerce and where great-power competition and warfare could become daily facts of life. That would be unthinkable in the Caribbean basin, which is home to only one great power and whose access to the Atlantic could never be shut off. (Try blockading the Lesser Antilles.) Suez supplies a second gateway to the larger maritime world, enhancing Mediterranean and North Atlantic countries’ prospects on the high seas immensely. That to me makes the difference.

Steven Solomon, author of Water: The Epic Struggle for Wealth, Power, and Civilization:

The canal with the greatest transformative impact on world history is China’s Grand Canal. Completed in 610 A.D. at the start of the Sui dynasty with the labor of some 5 million conscripted peasants, the 1,100-mile-long, S-shaped Grand Canal was the critical infrastructure that helped launch China’s medieval golden age.

By linking China’s Yellow River and Yangtze River basins into a unified, 30,000-mile inland waterway transportation network, China was able to supply surplus rice from its wet south to troops on its historically vulnerable, but arid northern border, thus providing its national security. River commerce and economic prosperity soared throughout China. Giant cities emerged. Government influence and internal communication — including distribution of the world’s first national newspaper — also improved. For well over half a millennium, China was by far the most advanced civilization on Earth; its influence reached throughout the Far East, India, and Arabia, and as far as the Mediterranean.

The most world-changing, geopolitical impact of the Grand Canal, however, began after the Ming dynasty completed the extension known as the “new” Grand Canal in 1411. With an inland transportation network that it believed could reliably provide for China’s economic self-sufficiency, the Ming decided to turn inward and seal off from the world.

Twenty years later, the dynasty abruptly terminated the expeditions of its invincible, large fleet of “treasure ships,” vessels 10 times larger and many times more powerful than Vasco da Gama’s, which would soon open Asia to European guns and trade. It was a turning point in world history. A great power, with the means to dominate all worlds it encountered and seaworthy enough to have crossed the Atlantic and Pacific oceans to Europe and the New World, suddenly decided not to press its advantage. How radically different world history would have been had China’s treasure ships pushed on to subordinate Europe or remained on patrol in the Indian Ocean to greet the small ships and cannons of da Gama in 1498!

William J. Bernstein, author of A Splendid Exchange: How Trade Shaped the World:

Gosh, that is a fun question. If you were to use the term “very narrow waterway” instead, that’s easy: It’s the Bosporus/Hellespont, without which Athens couldn’t have fed itself, and so the Persians would have defeated them. No Athens, no Western civilization.

My emotional favorite is the Panama Canal, of course, because it killed off sailing ships for good: The Cape Horn route was the last stronghold of sail because of sail’s advantage during the transition to steam over longer distances. Plus, Panama made the West Coast viable as an international entrepôt, which it sure wasn’t before 1914.

The Suez Canal, in contrast, had relatively little effect on East Asia and Australia/New Zealand trade, since it didn’t cut that much off the distance. The real difference was in trade with the subcontinent, where it cut the distance by almost half. But how important was India-U.K. trade in world history? Keeping India was likely a net economic drag on England.

Brian Fagan, professor emeritus of anthropology at the University of California, Santa Barbara, and author of Elixir: A History of Water and Humankind:

The obvious candidate for the most important canal historically is the Suez Canal, which was built after centuries of speculation by all kinds of people for strategic reasons, from the ancient Egyptians and Romans onward. But with the advent of supertankers and jumbo jets, it’s obviously less important than it once was, especially given current military strategies involving helicopters, drones, and cruise missiles.

The second obvious candidate is Panama and the proposed new alternative route. In the future, this will be more important, I should imagine, especially as we become less dependent on Near Eastern oil and as Asian markets assume ever-greater importance to global trade. And there’s the matter of a two-ocean U.S. Navy.

China’s Grand Canal that linked the north and the south for centuries in eastern China is an obvious candidate, especially in light of the current controversies over the massive waterworks proposed to link the Yangtze to water-starved northern China. If there’s one characteristic of Chinese endeavors over water, they have always been on a massive scale, and today is no exception.