When the Black Death came to Italy in 1347, it came on the Silk Road. When a novel coronavirus came to Italy in 2020, it, too, came on the Silk Road.

In the 14th century, it was rats and their fleas coming from central Asia, hitching on to overland caravans of spices and silk from China and India. Arriving in Crimea, the goods, and the bubonic plague, boarded galleys to Genoa, beginning centuries of struggle in Europe to contain the virus. They didn’t know what hit them, and in the years that followed, half the population died.

This year, the cause may have been the soft export of tourism—two early cases in Rome were Chinese tourists—or perhaps the luxury goods industry, which imports Chinese workers along with Chinese raw materials in order to ensure final products are “Made in Italy.” This time around, Italians already had a name for the disease—and knew its genetic structure.

You don’t get a pandemic without a global economy, and the economy has been global since well before the invention of jet planes. But does our current version of the global economy make the spread of disease—and its consequences—worse?

The problems, at least the big ones, are obvious: In the age of the jetliner, it takes just hours for an infected person to travel around the world, not many months. And in the age of the just-in-time global supply chain, the measures necessary to fight the spread of disease mean that illness in China can wreak economic havoc abroad before the virus crosses borders. US stocks swooned well before Americans woke up to the reality that the virus was already among them; investors knew that US companies depended on China for components and customers alike.

But “globalization” is not a choice we have made, it is a reality that we live in. North Korea, largely cut off from the world economy, became one of the first countries to seal its borders in response to Covid-19, but the coronavirus found its way from China, across the Yalu River, anyway. Now the so-called hermit kingdom has opened its borders to international aid, though it has yet to admit any cases.

The return of nationalist politics has left the impression that an interconnected world is a preference, something that can be shut off with the right border policies and tariff levels. But a thousand years of human history tells us that disease will find a way to spread. The good news is that alongside the vectors for accelerated spread of disease, interconnection has also given us the tools to fight it.

The bad news is we aren’t using them.

Our kind of globalization

“You caught me as I was sanitizing my phone,” University of South Carolina professor Michael Murphree greets me when I call him.

Murphree studies the economy of China and how trade has led to its outstanding growth in recent decades. He says the key difference in the global economy today in dealing with SARS-CoV-2 versus past epidemics, even those as recent as SARS in 2003, is the way that our manufacturing system has become distributed across the globe.

Consider the first pandemic the modern world has known: In 1918, in the closing stages of World War I, the Spanish Influenza came along—perhaps also from China—to compound the horror of the first global, mechanized conflict. Before the war, historians celebrated the latter stages of Pax Britannia as a first blush of globalization. Trade became increasingly important, and migrants between countries faced few restrictions, especially compared with today.

But that trade was different. It was often in finished goods or raw commodities—bicycles, say, or steel. “Today,” Murphrees said, “it’s who makes the chain, who makes the gears, who makes the lubricant, who makes the wires that go into the tires, all of this is in a fragmented value chain, dispersed globally.”

That’s why the measures taken by China to fight the epidemic have shaken the global economy more than they might have in a previous era. The virus broke out during the lunar new year, which likely helped accelerate its spread, but one small bonus is that many foreign companies who buy goods in China stockpiled extra product to get through the holiday-season slowdown. Now, manufacturers are learning that resiliency in an interconnected world will demand more diversified supply chains and deeper stockpiles.

Yet the movement in goods is not the only factor that sets today apart. While mass migration is less common today than in the past, the world’s prosperity depends more on travel—in the form of tourism, and for a variety of service industries including everything from accounting to entertainment. The Jet Age means the speed of that travel precludes previously effective health measures like turning passenger ships away at the harbor after a multi-week journey revealed disease on board.

More than in the past, we also are facing the unintended consequences of the economic machine we have built.

Anand Parekh, a former US health official and professor at the University of Michigan School of Public Health, says that researchers studying disease and globalization have been warning that unintended consequences of the modern economy will lead to more frequent pandemics.

Most obviously, climate change, driven by fossil fuel emissions, creates weather patterns more suitable to the spread of sickness. Then, there are simply more humans and more livestock on Earth than any previous time in history, giving microbes a larger breeding ground; as natural habitats are reduced, there is more contact between animals and humans. The increasing growth of anti-microbial resistance as antibiotics are overused on people, and particularly in agriculture, raises the specter of deadlier disease. And the logic of industrialization means more people are living in close proximity within mega-cities, allowing disease to spread faster.

How not to fight a virus

The Black Death was not understood by its victims, but they did employ the bluntest form of pre-modern disease fighting—the quarantine. Italian city states figured out that shutting off travel was the key to halting the advance of the disease. At the same time, these polities depended on trade for their very existence. Traders cut off from their customers had to choose between their lives and their livelihoods.

The original function of the first public health agencies, which emerged in renaissance Italy, “was to deal with merchants’ dissatisfaction with the lack of international coordination of health measures,” the economist Angus Deaton wrote in a survey of global development effects on health. “International public health has always been as much concerned with facilitating trade as with protecting health and, as many writers have noted, when the two come into conflict…trade tends to trump health.”

So it was with the responses to the epidemic in both China and the US, where governments of very different stripes each perceived political pain in the kind of heavy-handed response needed to halt the spread of a novel disease—preventing people from meeting each other in large groups. Neither country acted quickly enough. China missed its opportunity in late December when doctors in Wuhan began warning of a novel influenza, and the US dragged its feet on testing despite warnings from medical experts who watched deaths climbing abroad.

“China’s response was dramatic and draconian from our standards but effective, but unfortunately China wasn’t transparent and lost a lot of time between December and the first half of January,” Parekh says. “What has happened [in the US] is a black mark on the administration…[t]here are a lot of excellent people at the Department of Health and Human Services (HHS), career and political appointees, this is not their first time through this. It does seem to a certain extent that HHS was ready to lean forward, but the White House was not there.”

Economic data give us a taste of why: The production-prediction business has accepted that the world is now entering a recession. Governments faced a grim version of the marshmallow test psychologists use to explore delayed gratification—they can maintain economic production for now, risking further devastation, or take harsh measures in the near-term in an effort to avoid overwhelming their health care systems with patients in respiratory failure.

Decisions to ignore those advanced warnings—one of the key benefits the connected world has over the middle ages—is a reason why the outbreak is worse than it might have otherwise been.

Trade boosters see it as ironic: The world has built an exquisite machine to deliver both goods and viruses, but when we get the virus, we shut off the machine that brings us the products that could defeat it.

Take for example the tariffs imposed by Trump on China, which tax Americans who buy hand sanitizer, ventilators, medical masks and other key products to fight disease. We haven’t seen supply chains switch to other sources, according data analyzed by Chad Bown, a former White House trade adviser. Instead, American buyers have just paid more, in part because medical supply chains are highly regulated to ensure the safety of their products, making it difficult to get a new producer off the ground quickly.

As the epidemic spread, the Trump administration has begun granting tariff waivers to companies seeking to import these supplies from China; one of the first requests for tariff relief came on Jan. 31, two weeks after the first US case. The relief was finally granted in early March. US intransigence on trade may leave the country in a worse position to obtain critical goods when it needs them.

“If they are going to claim that supply chains can’t be tied up with China because pandemics cut them off, that’s fake news.” Bown says. “[The US government has] become unreliable in ways that are hurting us.”

The US isn’t the only place where reflexive protectionism could hinder the world’s response to the virus. Within the European Union, individual nations attempted to erect export limits on medical supplies before the European Commission moved to facilitate intra-European trade, potentially at the expense of other regions. But that could leave other nations, whether the US, China or the next outbreak zone, without access to those supplies.

“China and South Korea and Singapore are perhaps recovering sooner, not just because they got the disease sooner, but because they did a better job containing it,” Adam Posen, the president of the Peterson Institute for International Economics, says. “In an open world economy, they would be able to expand and take exports from the still suffering parts of the economy and thereby spread world growth. If we have a shut down world economy, then the earlier recovery of certain economies doesn’t do anyone else very much good.”

Americans are already turning to China and South Korea for medical equipment and tests—and likely paying tariffs.

Sanitary measures

The world faces daunting choices, but as anyone familiar with efforts to fight climate change is aware, solutions are unlikely to come if every country stands on its own. Even in the fantasy of autarky, where nations are entirely self-reliant, disease will spread—perhaps more slowly, but with the same devastation we saw in times past. Perhaps the most successful battle against disease, the defeat of smallpox, was only possible with international collaboration.

“What is required is not less globalization, but more, or at least more globalization of a different kind,” concluded Deaton, the economist surveying health and development. His answer? Information. “Deaths that can be prevented should be prevented, and they will be prevented if we can find faster ways of diffusing first-world health technologies, including the creation of the economic, educational, and political conditions that would permit their more rapid diffusion.”

We already have the means for this kind of diffusion, if not always the will. It’s the main advantage humans battling SARs-CoV-2 have over previous generations. When Chinese scientists had a DNA sequence of the virus, they were able to share it with researchers around the world nearly instantaneously.

One problem that characterized the poor response has been governments that are happy to reap the benefits of global connection, but rely on demonization of foreigners to solve domestic political problems—true of Xi Jinping and Donald Trump alike.

“The sharing of information from government to government is not always best, but the academic and the private community know what’s happening in China, we know what’s happening in Italy,” Parekh said. “Without that, we’d be replicating what doesn’t work or making the same mistakes.”

Already, vaccine production and testing are underway in numerous countries, and scientists are sharing potentially beneficial treatments on the internet, like the use of chloroquinine as a therapy for patients with Covid-19. A chilling forecast [pdf] prepared by epidemiologists in the United Kingdom, which predicted millions of deaths in the US absent drastic action, was what reportedly convinced the Trump administration to demand social distancing and prepare for serious economic consequences.

“No matter what you think the limitations are on cross-border epidemic spread, and no matter what you think you achieve by hoarding supplies, you make yourself more vulnerable if you are trying to be sole-source, self-reliant,” Posen says. “You don’t know what the next bug and the next technology and the next component is…But that’s all very rational. And like with the financial crisis a decade ago, the results are so bad, it just doesn’t sell.”

Governments that are reluctant to acknowledge their own faults are always eager to blame foreigners. Chinese diplomats now claiming, without evidence, that the coronavirus originated in the US as a bioweapon, and a coordinated response from the G-7 is foundering on US insistence that the virus be referred to as the “Wuhan virus.” That impulsive nationalism could limit effective global cooperation. Countries reluctant to acknowledge the crisis even declined to share their response to the virus with the World Health Organization, which in turn hesitated to name the virus a pandemic.

China, propaganda aside, is not giving up on globalization. Its government has prepared shipments of medical supplies to donate to Italy and other countries, while billionaire entrepreneur (and party member) Jack Ma has done the same in the US, which, by comparison, is missing from the international stage.

“China understands that in many ways its economy’s fortunes rely on those of its overseas partners,” Murphree says.”These are enormous sources of technology, sources of demand, sources of investment.”

And if China realizes its prosperity is tied into its global neighbors, perhaps US leaders can recognize that Americans’ health is linked to victims around the world.

“A virus is not contained by national borders,” Parekh cautioned. “It can maybe be delayed by actions taken at national borders, but it’s not going to be prevented.”