The new year could be, among other things, the Year of the Wall. President-elect Donald Trump is likely to be under pressure to honor his campaign promise to build a wall (or at least a fence) between the United States and Mexico along every inch of their 1,933-mile shared border. Few of his plans have drawn quite so much criticism, but history suggests that there is a certain method behind his apparent madness.
We live in an age of walls. In the 1990s pundits regularly celebrated the end of walls (along with the end of history), insisting that the fall of the Iron Curtain marked a new age of low borders and high interconnection. In many ways, they were right; cross-border flows of goods, people, capital and information have exploded across the last quarter-century.
However, in other ways they were wrong. The long-term historical pattern is that rich, developed societies build walls to bar people from poor, underdeveloped ones, either channeling trade and migration into controllable corridors or cutting them off altogether. During the Cold War, the rulers of the Soviet Empire turned this on its head, building walls to stop the subjects of their own relatively poor, underdeveloped societies from migrating to, trading with or learning from the rich, developed West — which, at least in theory, welcomed them. But since 1989, when the Berlin Wall came down, we have gone back to business as usual, with the wealthy once again building new barricades to keep the poor off their property. Rich, developed Israel has put up a security barrier to separate it from the poor, underdeveloped Palestinian territories; several European countries have built fences to separate themselves from Middle Eastern migrants; and now, of course, the United States plans to tie together the bits of wall it has already built to create a continuous curtain separating itself from Mexico.
That none of this behavior is new suggests that those who build walls and those who want to breach them might learn something useful from looking at the long history of barrier-making. This applies particularly to the most famous case of all, the Great Wall of China.
For many years, archaeologists traced wall-building all the way back to 9300 BC, when villagers at Jericho, located in what is now the West Bank, put up a wall to protect their oasis home from raiders. It is now clear that the original excavators actually mistook a series of small barriers against floods, built over the course of many centuries, for a single fortification. By 4300 B.C., however, the town of Mersin in southeast Turkey definitely had a simple fortification wall, and by 3100 B.C. Uruk in southern Iraq had a wall 5 miles long, studded with strong towers. Around 2200 B.C., King Sharkalisharri of Akkad — also in Iraq — built the first genuine frontier barrier, roughly 50 miles long. This was intended to fence off his territory from semi-nomadic Amorite raiders. Sharkalisharri even called it "The Repeller of Amorites."
Far from being the polar opposite of openness, walls are complementary to globalization.
Advocates of integration normally condemn modern wall-building, but long-term history makes one point very clear: Far from being the polar opposite of openness, walls are complementary to globalization. As flows of goods, people, capital and information accelerate, rich and poor societies become more entangled. Plenty of people welcome the entanglement; others even seek it out. But it has always disconcerted and threatened those ensnared by it, creating losers as well as winners. People in rich and poor societies alike have, unsurprisingly, looked for ways to control and manage entanglement — which is where walls come in.
The premodern golden age of walls, which began roughly 2,000 years ago, was also the premodern golden age of globalization. The Romans in Europe and the Han in China each created empires with 50 million-60 million subjects and with economic networks that stretched across Eurasia. And yet Roman emperors (especially, but not only, Hadrian) built walls to keep out barbarians, and China's first emperor built the prototype of what we now call the Great Wall.
It is no coincidence that the high points of open borders and closed barriers tend to coincide. Even the most avid globalizers rarely want to globalize everything. They have generally recognized that the free movement of people is the most destabilizing part of the package. They have, accordingly, favored barriers in this regard while advocating openness in others. But this was always easier said than done.
Such was the case with China's Great Wall. By general agreement this is one of the wonders of the world, even if the old story that it can be seen from outer space is untrue. Neil Armstrong thought he had seen it from the surface of the moon in 1969 but was actually looking at a cloud formation. (China's government conceded this only in 2003, when Yang Liwei, the first Chinese astronaut, admitted that he had looked hard for the wall but could not find it.) Nonetheless, the wall's greatness was well-established in Western thought by 1972, when President Richard Nixon visited it and announced "This is a great wall and it had to be built by a great people."
A Surprising Verdict
This verdict would have surprised the people who actually built the wall. China's emperors normally saw walls as admissions that they could not manage their northern frontiers properly in the face of fast-moving nomadic horsemen from the Mongolian steppes. The Chinese learned early on that managing a long, open frontier is a complicated business, because the reasons people want to cross it, the methods they use and the consequences of their actions vary so much.
Immigrants moved into China in four main ways, each with its own rationale.
The first pattern involved young men—sometimes individually, sometimes in gangs—coming as economic agents or migrants, looking for work or for a chance to trade within the wealthy empire. But if they could not find what they needed, or simply if the opportunity presented itself, they might turn to violence, killing and robbing defenseless peasants along the frontier.
The second pattern of immigration involved families. When times were hard on the steppes—or, once again, if opportunities presented themselves—single families or larger groups might migrate in the hope of being given land to farm, perhaps in return for paying taxes or agreeing to serve in the army. Families were usually less alarming to the empire than young men, but if things went wrong (Chinese border officials were often tempted to trick immigrants or sell them into slavery), their desperation could make them much more violent than any gang of robbers.
The third reason for nomads to come was war. The quickest route to the top for steppe chieftains on the make was to win wars along China's frontiers, picking up enough fortune and glory to entice other chiefs to sign on as their followers. But even chiefs who were risk-averse could conclude that war was their least bad option if they feared that Chinese armies were about to attack them. Full-blown wars were much less common than disorganized incursions of young men or families, but much more devastating: In 1215 Genghis Khan sacked 90 cities in northern China and left Beijing burning for a month.
Finally, and rarest of all, there was conquest. Even the most bellicose nomads normally just wanted to get rich and then ride back to their homes on the steppes, not to overthrow the Chinese Empire. When China's Han dynasty collapsed in the face of invasions in the 3rd century AD, the tribesmen who overran it seem to have been genuinely horrified at what they had done. They neither knew nor wanted to know how to run the complex agrarian empire that they had just destroyed, let alone how to manage the sprawling bureaucracy that raised and spent taxes. China promptly collapsed into the anarchic, violent era that its historians called the age of the "Sixteen Kingdoms of the Five Barbarians." A thousand years later, Genghis Khan was also in a position to conquer China but had more sense than to do so. Only a very rare nomad — such as Genghis' grandson Kublai Khan in the 1270s and the Manchus who founded the Qing dynasty in the 1640s — had the skills to do so and make it work.
The latter two strategies — war and conquest — are obviously not very relevant to 21st-century wall-building. As I observed in an earlier column, the main way in which ancient migrations differ from modern ones is the massive imbalance in power in modern times between rich governments and the people trying to cross their borders. Mexican migrants do not have the option of calling on armored divisions to clear their path to San Diego, let alone of annexing the United States and running it from Mexico City.
In the rare cases where something like a war has erupted across borders protected by walls, the walls themselves have never been more than just one part of the broader security strategy of the richer, more developed side. Just look at the Gaza Strip in 2014. Israel's security barrier did shut out Hamas terrorists, but the Iron Dome anti-missile system and incursions into the strip arguably mattered even more.
This, too, seems to be part of a long-term pattern. Chinese rulers always combined walls with two other strategies, the first being pre-emptive war. In this approach to security, walls deterred low-level threats from individuals and families while massive military operations prevented higher-level threats emerging from rival nomadic states on the steppes.
The mastermind behind the walls-and-wars strategy was China's first emperor, who united much of the country in 221 B.C. and was subsequently buried with the famous Terracotta Army. He saw wall-building as a means of offense rather than defense, and his original version of the Great Wall brought vast tracts of the steppes inside China, effectively annexing much of the nomads' most important territory. But this approach actually had the opposite effect from what he intended: Threatened with starvation, nomads formed a great federation and mounted massive invasions of China. In 200 B.C. China hit back with its own invasion of the steppes, only to lose perhaps 100,000 men in battle and another 100,000 to frostbite.
Following this disaster, China added a second strategy — bribery — to wall-building and pre-emptive war. When nomads robbed and raided villages, the frontier provinces found it harder to pay their taxes, and responding by building walls or sending out armies cost a fortune. So, emperors reasoned, why not just pay the nomads to stay away? So long as the cost of bribes came to less than what the empire would lose through reduced tax payments or would spend on walls or troops, bribery paid.
Bribing nomads, however, had the same drawbacks as any other kind of extortion racket. There is a saying in Chicago politics that an honest man is one who, when you buy him, stays bought. But steppe chiefs did not play by these gentlemanly rules. Regularly, they took their bribes and then raided anyway.
'Small of Virtue'
Managing the frontier was a delicate business. The most skilled emperors and civil servants learned to use carrots and sticks, handing out just enough bribes, going to war just often enough and building walls just strong enough to keep the plundering at the level of a tolerable nuisance rather than a threat to the empire's integrity.
Relying on walls alone was a strategy of last resort. The brick-and-stone version of the Great Wall you would see today if you took a tour bus from Beijing to Badaling, for instance, was the byproduct of a military disaster in 1449. That year, after a decade of mismanaging the frontier, Emperor Zhengtong launched a great invasion of the steppes that went so badly that the Mongols actually captured him. With all alternatives apparently having failed, work on a new and improved Great Wall accelerated, accompanied by an upswing in anti-Mongol racism. Mongol dress and speech were banned in Beijing, and ordinary Chinese increasingly looked at immigrants from Central Asia with suspicion. Violent attacks and expulsions became common as the wall went up.
The wall took more or less its modern form under Emperor Jiajing, who reigned from 1522 to 1567. By general agreement, he was a terrible ruler, a paranoid, narrow-minded bully. To crack down on the Mongols, he cut off all trade and migration, but the consequences were disastrous on the Chinese as well as the Mongolian side of the border. Poverty soared, riots occurred regularly and the state budget spiraled into the red. And despite these disasters, the wall did not really work. Immigrants kept finding cleverer ways to get in. Jiajing responded by building more walls, until by the 1570s a continuous barrier ran for 4,000 miles along China's northern border.
The expense was staggering. In 1576, the wall absorbed 75 percent of government income. Unsurprisingly, it was always underfunded, undermanned and under construction, and when its biggest test came it proved useless. Morale had collapsed among the border guards, who, as the wall's historian Julia Lovell describes it, "realized they were building endless, useless walls around an irredeemably decayed political centre." Manchu attackers breached the wall in April 1644, entering Beijing less than three weeks later. There they found that the emperor had hanged himself, after pinning a note to his robes: "I, feeble of mind and small of virtue, have offended against Heaven … Ashamed to face my ancestors, I die."
Since then, no Chinese ruler has made much of the Great Wall — until 1972, when, in denial of history, Richard Nixon made it the symbol of China's success.
President-elect Trump recognizes that there are lessons in the Great Wall of China. "You know the Great Wall of China, built a long time ago, is 13,000 miles," he told Bill O'Reilly of Fox News in 2015. "I mean, you're talking about big stuff. We're talking about peanuts, by comparison, to that." The lesson to draw from China's Great Wall, he seems to be suggesting, is that building a Great Wall of America will be easy, because it will be shorter than China's ("Well, it's 2,000 miles but we really [only] need 1,000 miles," he says) and modern technology will make the task simple. "They didn't have Caterpillar tractors," he correctly observes, adding "I only want to use Caterpillar, if you want to know the truth, or John Deere." The construction of China's wall, by contrast, was so arduous that — according to folktales — one worker died for every yard built. "If you have a son, don't nourish him," one ancient poet said. "Can't you see, the Long Wall is propped up on skeletons?"
It seems to me, though, that the lessons of the Great Wall of China are rather different. Border walls have always been a way for rich, developed states to respond to the instability globalization creates, and we should not be surprised by their renaissance in the 21st century. However, no wall — certainly not China's — has ever been a standalone solution. All have worked only as part of a larger security system, involving diplomacy (especially bribery) and force (especially pre-emptive war), both of which bring problems of their own. Further, although walls can curb the chaos that uncontrolled migration brings, they also generate chaos of their own, destabilizing both sides of the border and creating new sets of winners and losers. If 2017 does turn out to be the Year of the Wall, we should brace ourselves for a bumpy ride.