A Mexican migrant talks to a family member through the border fence between Ciudad Juarez and El Paso, United States, after a bi-national Mass in support of migrants in Ciudad Juarez, Mexico.Jose Luis Gonzalez / Reuters

What does fear accomplish?

It’s a question the Trump administration appears to be trying to answer, whether intentionally or not, as it cracks down on illegal immigration.

Just last week, The Washington Post reported that the administration is considering separating parents from their children if they’re caught crossing the border illegally. If implemented, the policy would mark a shift from current policy, which keeps families together. The move has received pushback from immigrant groups who argue it’s cruel, but administration officials see it as a way to discourage Central American migrants from making the journey to the United States following an uptick in family units and unaccompanied children caught at the border. Even if the policy successfully deters economic migrants however, immigrant advocates warn that it will punish the most desperate immigrants—those fleeing violence or persecution—without dissuading them.

The number of apprehensions at the U.S.-Mexico border dropped at the start of the Trump presidency, but has since begun to creep up again, according to Customs and Border Protection figures. In March, the Department of Homeland Security reported a 40 percent decline in apprehensions from January to February. Indeed, it appeared the mood had shifted in Central America as Trump took office. In speaking with migrants, advocates, and workers at shelters in the U.S. and Mexico, The New York Times found that people were less likely to make the journey north.

In March, then-Department of Homeland Security Secretary John Kelly attributed the drop in border crossings to the new policies rolled out under President Trump. “Since the Administration’s implementation of Executive Orders to enforce immigration laws, apprehensions and inadmissible activity is trending toward the lowest monthly total in at least the last five years,” Kelly said in a statement. Then, in November, U.S. agents caught 7,018 families, an increase from 4,839 the month before, according to CBP. The number of apprehensions of unaccompanied children also increased.

While it’s not the first time the U.S. has tried to discourage migrants from making the trek to the southern border, the proposed measure raises questions about the effectiveness of deterrence policy and how far an administration is willing to go to keep migrants at bay.

The United States has long relied on deterrence policy as a way of dissuading migrants from entering the country illegally. This has been true under Democratic and Republican administrations alike. In 2014, following a surge of Central American migrants at the U.S.-Mexico border, the Obama administration tried to discourage migrants from heading to the border through an ad campaign. Customs and Border Protection warned anyone considering coming north that it was too dangerous and that entering illegally would preclude them from obtaining legal status.

To some degree, it’s also what administrations try to achieve with deportations. By facing the threat of deportation, and with that, possibly being separated from their family, migrants may be less likely to try to cross the border. Immigrant advocates criticized Obama for adopting this strategy in 2016. And it’s what the Department of Homeland Security appeared to be doing when it reversed the Obama administration priority system to cast a wider net on undocumented immigrants eligible for deportation. (Overall, the number of removals decreased in fiscal year 2017 compared to the previous year, though arrests increased.)

But what deterrence policy, or any attempt to stoke fear among migrants, may not take into account are the circumstances in their origin countries that drive migration in the first place. “It’s hard to think that a family—a mother fleeing with her children who is quite literally trying to save their lives—is going to be deterred by being separated from her children,” said Maureen Meyer, the director for Mexico and migrant rights at the Washington Office on Latin America.

The factors that drive migrants to come to the United States  differ for each individual. Some migrants may be seeking economic opportunity, while others are fleeing violence. The difference is that one group might be more willing to stay back than the other. “People who could afford to wait it out, do so,” Meyer said. “But those fleeing violence continue to seek protection in the United States and other countries in the region.”

According DHS statistics, of the 303,916 apprehensions along the southwest border in fiscal year 2017, 162,891 were from El Salvador, Guatemala, and Honduras, which has one of the highest murder rates in the world. And 127,938 were from Mexico. The uptick in asylum requests indicates that several border crossers are facing dangers within their native countries that they’re trying to escape. (Earlier this year, migrants-rights groups reported that the administration was turning away asylum seekers at the border. CBP denied any change in policy.)

Still, immigration restrictionists believe that fewer migrants would embark on the trip north if the administration were to implement the family separation policy. “The parents that would undertake this perilous journey to the United States would be less likely to do it if they knew they would be separated from their kids,” Andrew R. Arthur, a resident fellow at the Center for Immigration Studies, which supports reduced immigration, told the Post.

Any change to U.S. immigration policy is likely to alter the flow of migrants to the country, though not always in the way that might be expected. In a 2016 article called “Why Border Enforcement Backfired,” Douglas Massey, a professor of sociology and public affairs at Princeton, Jorge Durand of the Centro de Investigación y Docencia Económica in Mexico City, and Karen Pren, the manager of the Mexican Migration Project at Princeton's Office of Population Research, found that increased border enforcement led undocumented immigrants to stay in the U.S. for a longer period of time.

“It’s clear that U.S. immigration policy has a pretty dramatic effect on the migration flow of immigrants either to encourage or discourage [migrants], sometimes in ways that weren’t anticipated,” said Tom Gjelten, the author of A Nation of Nations: A Great American Immigration Story.

The proposal to separate children from their parents also poses another set of challenges. The Department of Health and Human Services, which keeps undocumented children in shelters until they find a sponsor, is already overwhelmed—a problem that could be exacerbated if more children are sent to their shelters. And families, afraid to risk separation at the border, may be vulnerable to traffickers and smugglers.

The policy is not yet a done deal. The proposal has reportedly been approved by Immigration and Customs Enforcement, but DHS Secretary Kirstjen Nielsen has yet to sign off on it. At the very least, however, the measure falls in line with the administration’s approach to immigration: stoking fear among potential migrants to keep them from coming to the United States illegally.

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