The decision to flee one’s country is never made easily, and leaving is rarely simple. In northern Mexico, along the United States border, we’ve met Hondurans who spent years saving up the money to make the trip; Salvadorans who walked for months; Haitians who crisscrossed countries to make it to the border. Every year, thousands of asylum seekers from countries like Russia, China, Romania, and India travel tens of thousands of miles to try to cross the border in northern Mexico. One of the most established refugee routes starts further south: We’ve met people escaping ethnic violence in Cameroon who flew into Quito, the mountainous capital of Ecuador, and then trekked hundreds of miles north through swamp and jungle to make it to the United States.

For almost all of the people who made this kind of journey but were unlucky enough to complete it in the past two months, their time in this country has lasted less than a few hours before they were summarily—and illegally—deported back into Mexico. Since March 21, the Trump administration has sent over 20,000 people back across the border, thousands of whom would have otherwise sought refugee protection. In that same time, only two people were allowed to stay to seek asylum.

One of the earliest victims of the coronavirus pandemic in the United States was the country’s refugee system. On March 20, the Trump administration announced a sweeping and unprecedented order: Instead of processing new arrivals for asylum, the Border Patrol was encouraged to deport them as rapidly as possible. The United Nations said the decision was illegal under international law; advocacy groups and elected officials called the new policy a travesty. The administration defended the move, claiming it was only a temporary, 30-day measure to prevent the spread of the coronavirus. But the rapid expulsion policy remains in place, almost two months later. It has not yet been challenged in court.

While the administration has justified the end of asylum on the border as a necessary public health measure, it’s not hard to see the ways in which the pandemic is merely the pretext for the order, not the motivation. “From its earliest days, one of the Trump administration’s chief objectives has been overturning and circumventing US laws that were designed to protect refugees and people seeking protection, as well as unaccompanied children,” says Eleanor Acer, the senior director of refugee protection for Human Rights First. “It’s now using the pandemic as yet another weapon to try to circumvent US asylum law.”

On May 13, Human Rights First published a detailed report exploring the effects of the new effective asylum ban, with research based on interviews with asylum seekers in Mexico and legal experts on both sides of the border. The report found that the United States has forced over 1,000 unaccompanied children back into Mexico to fend for themselves; it also discovered that many people have been kidnapped, raped, or assaulted once returned to Mexico. The legal analysis was unambiguous: The expulsion policies “violate U.S. asylum, immigration, and anti-trafficking laws, due process protections, and binding treaty obligations. U.N. Refugee Agency (UNHCR) legal guidance makes clear that a public health emergency cannot justify ‘blanket measure[s]’ blocking asylum seekers.”

Why, despite its clear illegality, has the total asylum ban remained in place? Scholars of immigration say the administration has capitalized on two things: the current crisis, and over 100 years of anti-immigrant propaganda casting immigrants as diseased.

Organizations that would typically challenge the law, such as the American Civil Liberties Union, are in disarray, as they deal with the shock of multiple emergencies and a pandemic that is impacting their lawyers across the country. However, even after the intensity of the shutdowns and quarantines wear off, advocates worry that fears of “diseased” outsiders will make Americans—including those who otherwise support the institution of asylum—more willing to give up on refugee law: Foreigners will simply be seen as too dangerous to admit, no matter the circumstances.

Immigration policies have often become more restrictive in the wake of crisis. After the September 11 attacks, refugee resettlement was briefly halted. Less than a year after the attacks, two new militarized agencies were created to apprehend and detain both unauthorized immigrants and asylum seekers: Immigration and Customs Enforcement and Customs and Border Protection. Worldwide, the 2008 economic crisis and the 2015 European migrant “crisis” led to massively increased hostility towards migrants and the abrogation of EU obligations regarding migrants.

“Crisis produces an instinct to close the border and keep people out,” says Charanya Krishnaswarmi, Amnesty International’s advocacy director for the Americas.

But the Covid-19 pandemic might create long-term damage to refugee law in ways other crises have not: Sickness provides a convenient pretext to mask xenophobia. Even in the best of times, immigrants are seen by those seeking to limit immigration as a threat to “our” culture, “our” economic well-being. Now, the risk of a deadly virus means the outsiders can be presented as an existential threat as well.

Historically, anti-immigration proponents have often used the threat of illness to justify calls to end both refugee protections and immigration. An outbreak of bubonic plague in San Francisco’s Chinatown was one of the precipitating events that led to the racially motivated Chinese Exclusion Act of 1882, which all but barred Chinese immigration. On New York’s Ellis Island, European immigrants underwent medical exams and those deemed disabled or diseased were summarily deported. Chinese immigrants, when they were able to make it to the United States at all, often fared far worse: In the first half of the 20th century, Angel Island, in the San Francisco Bay, was used to quarantine Chinese and other Asian immigrants, subjecting them to humiliating medical exams that included analyzing a stool sample to prove they were free of parasites and diseases.

More recently, Stephen Miller, President Donald Trump’s chief adviser on immigration, has encouraged the president to play up fears of disease among Central American migrants to restrict asylum. During the 2014 West African Ebola crisis, conservative Republicans—without any evidence—accused Mexican and Latin American migrants of bringing the disease over the southern border. When two prominent migrant “caravans” arrived on the southern border last fall, one Fox News guest fanned fears that the Central American migrants would bring “leprosy” into the country.

In the last two decades, across the world, political leaders seeking to limit immigration have found success in playing up public health fears, a strategy human rights scholars have studied for years, and which we call “medicalized migration.” Fears of both migrants and disease have led to the medicalization of borders on six different continents, with the implementation of medical examination, required vaccines, testing, and quarantine.

In the current crisis, these supposedly “medical” fears haven’t been equally applied: Even as the United States moved to ban asylum seekers in the early days of the pandemic, hundreds of thousands of Americans were permitted to return from abroad, often through airports with little to no screening measures in place.

It goes without saying that medical measures such as quarantines and inspections are vital tools in the current pandemic, but doctors are clear that the implementation of such measures is useful only when guided by public health science and not politics. As US citizens living abroad have flown home without so much as a temperature check, immigrants and refugees have been subjected to draconian medical measures—a difference that betrays the administration’s politicization of medical responses to the pandemic. The administration’s hesitance to place the same measures on citizens and noncitizens hampered its handling of the pandemic, wasting precious time that could have been used to help contain the virus. This unequal and punitive application of medical screenings has therefore been just one more way the administration has botched its response to the virus, and may be one with the most lasting effects.

In the initial phase of the pandemic, travel restrictions to and from China became widespread, with some 96 countries instituting travel restrictions. Now, almost 90 percent of the world’s population live in countries with some kind of travel restriction on travelers who are neither citizens nor residents. Widespread testing on arrival and mandated quarantine or self-isolation measures have been implemented from Japan to Australia. Although governments the world over have cited concerns about health and safety when announcing Covid-19 policies, they have clearly prioritized the health and safety of their own citizens over those of other countries. The suspension of asylum hearings in the United States, along with the continued deportation of migrants, and the refusal to shut detention centers, demonstrates a willingness to imperil the health and safety of noncitizens in the name of public health.

On April 21, the president announced plans to “temporarily suspend immigration into the United States” in a move Democrats have called “xenophobic scapegoating.” Covid-19 has made tangible the parallels the president himself has drawn between migrants and disease, and given such claims a veneer of legitimacy. Medicalized migration reinforces this connection between immigrant and threat, while simultaneously buttressing the inequalities between citizens and noncitizens.

What does this mean for the future of refugee law? Human Rights First’s Acer, like other refugee experts we spoke to, suspects that the new, total asylum ban will last long after the coronavirus pandemic ends. “I expect they will fight to make it last as long as this administration, however long that is,” she says.

“The fear is these measures will be in place long after pandemic ends,” Krishnaswarmi, of Amnesty International, said.

However, even if asylum is reinstated on the southern border (for instance, under a hypothetical Democratic administration), Acer worries that the pandemic-inspired exclusions policy might have already done significant damage to international refugee protections. “What I’m worried about now is how countries like Hungary and Turkey will be emboldened to further refuse refugees,” she says. The language of public health creates a convenient narrative for anti-immigrant zealots like Hungarian President Viktor Orbán to obscure racist and Islamaphobic rhetoric with the language of medical necessity.

The Trump administration’s cynical use of the pandemic to further its anti-immigrant agenda is not unique: Far-right groups in Italy, Austria, France, and Germany have all drawn links between foreigners and Covid-19 in an attempt to pressure governments into more-discriminatory immigration policies. With dwindling supplies of PPE and no vaccine in sight, such policies are likely to continue as governments and panicked populations face the economic and biological impact of reopening borders. The existential threat of Covid-19 has prompted a swift retreat to the nation-state, at the cost of international human rights, as countries rush to fly their own citizens home while keeping others out.

This has produced a slow-moving crisis in the making: As devastating as the impact of Covid-19 has been on the Global North, its spread into the Global South threatens suffering on a scale not yet seen, and could fuel the next generation of mass movement out of Latin America and Africa. Now, those seeking to escape the economic, social, and medical ravages wrought by Covid-19 are likely to come up against immigration policies unprecedented in their hostility and suspicion of foreigners.