Now that President Donald Trump forced a government shutdown over his proposed wall along the Mexican border, it’s worth taking a moment to examine other big walls in history. Let’s break it down:
Great Wall of China
This massive series of fortifications across China’s historical northern border was designed to stop raids by tribes that lived in the Eurasian Steppe. The project began as a series of smaller walls that gradually interlocked into the Great one. Much of this work took place during the Ming dynasty.
The Great Wall featured towers and garrison stations, and it did repel some raiders, but it ultimately failed at key points. For example, Hong Taiji, emperor of the Qing dynasty (fiercely opposed to the Ming dynasty), managed a spectacular breach in 1629. The Qing armies repeated that feat in 1642, on their way to overthrowing the Ming dynasty two years later.
While the wall was spectacular (bigly!), such a defense is only as good as the forces defending it—and if those forces are pulled in too many ways at once, the wall will fall.
Come to think of it, maybe the Great Wall of China isn’t a fantastic example. Let’s try…
Hadrian’s Wall (aka Roman Wall)
So the Romans conquered the modern-day U.K. Well, they kind of conquered it. There was the slight problem of the northern part of the country, which remained under the control of groups such as the Picts. These ancient Britons hated the Romans to a hilarious degree and showed it by raiding the South as often as possible.
Around A.D. 122, the Roman Emperor Hadrian got tired of the Britons putting the heads of Roman soldiers on pikes, so he ordered the construction of an enormous wall across the middle of the country. This 73-mile “belt” of earthworks and stone, dotted with ditches and forts and other defensive structures, was well-built—stretches of it survive today—but it wasn’t very good at repelling the attacks from the North. In fact, some historians theorize that the wall wasn’t designed just to stop those raids, but also to control taxation and immigration. There’s no place like a checkpoint through a massive barrier to set up a taxation station.
Hadrian died in 138, and his successor, Antoninus Pius, decided he didn’t want to continue building Hadrian’s Wall; he wanted his own wall. And so the Romans began constructing yet another wall a little further north. This failed to calm the ornery tribes of the North, and when Antoninus Pius kicked the bucket, his successor, Marcus Aurelius, retreated back to Hadrian’s Wall.
In the end, the wall failed to stop raids, and soon the Roman occupation collapsed due to a number of issues. The locals used the stones from the wall to build their own little walls and houses.
Well, Hadrian’s Wall wasn’t a 100 percent success. Let’s try a more modern one. How about…
Walls of Constantinople
When Rome fell, Constantinople (modern-day Istanbul) became the seat of the Roman Empire. Faced with threats from all directions, emperors such as Constantine the Great felt the need to erect the world’s most elaborate defense system around the city. They spared no expense; huge walls eventually shielded the citizens from the surrounding land and sea.
Throughout history, no wall has offered 100 percent impermeability.
To be fair, those defenses managed to protect Constantinople through any number of sieges and attacks. In fact, after a few centuries, those tasked with maintaining the defenses were feeling pretty good about themselves. What could possibly penetrate this fantastic setup?
The Ottoman Empire had one word for them: gunpowder.
Those mighty walls might have resisted arrows, tunnels, siege machines, and boats, but cannons could tear right through them. In 1453, the city fell, and as the old song goes: “Now it’s Istanbul, not Constantinople.”
Over the past six centuries, artillery has progressively made walls more and more obsolete as effective military fortifications. Um, maybe we should choose a more modern example of a wall…
Israeli West Bank Barrier
This barrier runs some 440 miles, separating Israel from the West Bank, and sometimes running through the West Bank itself. Large sections aren’t so much a wall as a series of fences and barbed wire, but there are places where concrete reaches more than 25 feet high. The concrete walls are supposed to help block sniper fire, and the barrier as a whole is designed to prevent anyone sneaking through. In addition to the walls and wire, there’s a massive system of sensors, patrols, anti-vehicle ditches, and other countermeasures.
Although the barrier is highly controversial (demonstrations against it have taken place around the world, and Palestinians routinely refer to it as an “apartheid wall”), Israeli officials have insisted for years that it has cut down on the number of intrusions into Israeli territory. (Israel also maintains fencing along the Egyptian and Lebanese borders, as well as the Gaza Strip.) But attacks haven’t dropped to zero.
According to the New York Times, the barrier has also proven ineffective at keeping tens of thousands of Palestinians from passing through “to work in construction, agriculture, or service industries in Israel, either through gaps in the route or by utilizing the services of local smugglers.”
So, um, maybe that one didn’t totally work either.
What Does This Mean for Trump’s Wall?
President Trump insists that a massive physical wall—whether built of concrete or some kind of metal slats—will totally stop illegal immigration into the United States via Mexico. He also believes that a “big, beautiful wall” will prevent drug smuggling, despite a long history of cartels using tunnels, boats, aircraft, mules with U.S. passports at legal points of entry, and even catapults to bypass barriers.
Plus, the U.S.-Mexico border is a long one, and many miles of it run through uninhabited land. Even if we deploy more border patrol agents, supplemented by drones and sensors, it seems like a difficult proposition to constantly monitor every inch of it. Those who want to get through will exploit the weak spots and trust that U.S. personnel will be too overstretched to catch them. Hey, it worked for the Britons trying to get through Hadrian’s Wall!
Throughout history, no wall has offered 100 percent impermeability. No matter how sturdy or big the wall, humans will figure out ingenious ways to get through, under, or over it. Somebody tell the president.