Over the past few weeks, the U.S. government has gone into crisis mode in an attempt to stop the flow of migrants attempting to cross the country’s southern border illegally or to apply for asylum at border ports. The Department of Justice declared a “zero tolerance” policy that would subject anyone caught crossing the border between ports of entry to criminal prosecution, and the Department of Homeland Security (DHS) began separating children from their parents so that the latter could quickly go into criminal proceedings. After considerable public outcry, President Donald Trump ultimately suspended family separation in favor of a dubious plan of family detention, but he has continued to speak and tweet repeatedly about what he considers to be a border that is out of control.

What makes this sudden attention to the border so unusual is that there are now fewer people trying to cross illegally than at any time since the early 1970s, for two reasons. Not only has Mexico ceased to be the source of most migrants trying to cross the border but it has become a largely effective buffer against the newest migration flows from Central America.

With the election of the left-of-center nationalist Andrés Manuel López Obrador to the Mexican presidency, however, the status quo could soon change. López Obrador has made it clear that he does not want Mexican immigration policies to be merely an extension of U.S. enforcement policies, and continuing the current Trump administration practice of simply berating the Mexican government to do more to stem the flow of migrants will likely only make things worse. Going forward, Washington needs to work with Mexico to form a more cooperative and comprehensive migration strategy. Otherwise, the United States could find itself facing a much larger flow of undocumented immigrants at the southern border than it does today.


Last year, there were fewer people apprehended at the border than at any time in 46 years, and even with a slight jump in apprehensions this year, the overall number still remains at historically low levels. Moreover, DHS estimates that today it successfully detains a far greater percentage of unauthorized border crossers than ever before, meaning that the real drop in crossing attempts is likely even greater than the apprehension numbers indicate.

There are two reasons for this dramatic decline in unauthorized crossings. The first is well known. Mexicans once constituted almost all of the undocumented immigration flows, but today they make up less than half, and their numbers keep dropping year after year. This is because over the past two decades, average income in Mexico rose by about a third, years of schooling increased by half, and life expectancy increased by four years as a result of better access to health care. These changes were hardly an economic miracle, but they were just enough to convince most people that it wasn’t worth making the dangerous journey northward. In addition, money that Mexican immigrants living in the United States sent back to their families and home communities also helped provide opportunities for the next generation so that they wouldn’t have to migrate.

The second reason so few people are attempting to cross the border is less well known. Over the past five years, migrants from Guatemala, El Salvador, and Honduras, three of the region’s poorest and most violent countries, have constituted the majority of unauthorized U.S. border crossers. Although some of these migrants make it to the U.S. border, an even larger number do not. Our calculations at the Migration Policy Institute suggest that the Mexican government has deported more people to Central America than the U.S. government since 2014, the year that the significant Central American migration flows started. Mexico itself is also increasingly becoming a country of asylum for Central Americans, receiving 8,656 applications last year from nationals of those three countries, up from 1,769 in 2014. And there is some evidence, though most of it still anecdotal, that increasing numbers of Central American migrants are staying in Mexico rather than trying to cross into the United States.

Some of Mexico’s enhanced immigration enforcement responds directly to concerns of the U.S. government. When the surge in Central American migration happened in 2014, Mexico implemented a Southern Border Strategy, which increased infrastructure and the number of immigration agents at the border with Guatemala. It was an effort that received some logistical and financial support from Washington. The U.S. government certainly put pressure on its Mexican counterpart to do this, but the Mexican government also had its own reasons for designing and implementing the strategy. One was undoubtedly the desire to take pressure off the border with the United States in order not to torpedo other areas of the bilateral relationship, including the potential for future U.S. immigration reform that could have benefited Mexican-born undocumented immigrants already in the United States.

Mexico is now far more a country of transit and destination for immigrants from other countries than it is an immigrant-sending nation.

At the same time, Mexico is now far more a country of transit and destination for immigrants from other countries than it is an immigrant-sending nation. (Several other countries around the world, including Turkey and Morocco, have undergone a similar shift.) Central Americans have been the most visible group crossing through Mexico and occasionally staying, but the largest number of immigrants in Mexico actually come from the United States. There are now somewhere around a million U.S. citizens living in Mexico, if not more. Some of them are the children of Mexicans who have returned to their parents’ home country, but many others have moved to Mexico to pursue either job opportunities or a comfortable retirement.

Between these two flows—the migrants coming northward from Central America and those coming southward from the United States—Mexico has been forced to come to terms with its own need to have a proactive immigration policy, around both legal and undocumented immigration flows. This, in turn, has spurred internal debates on everything from visa policy to immigration enforcement, leading to a major new immigration law in 2011. But until recently these debates largely happened out of public view, among a handful of political leaders, agencies within the Mexican government, and immigration advocates.


Now, both the style and substance of Mexico’s immigration strategy may be about to change. The images of families being separated at the U.S.-Mexican border—almost all of them Central Americans, although there were a handful of Mexican families affected—came right as Mexico’s presidential campaign was in its final stretch. It pulled the country’s quiet backroom debate on immigration policy out of the shadows and into public discussion for the first time and forced all of the candidates to take public positions on what they would do about Central American migration flows if elected. On the campaign trail, López Obrador said that the Mexican government needs to show greater respect for the rights of migrants, to find ways of integrating those who stay in Mexico into productive sectors of the economy, and to invest in the economies and institutions of Central American countries so that people stop leaving.

Presidential candidate Andres Manuel Lopez Obrador gestures as he addresses supporters after polls closed in the presidential election, in Mexico City, Mexico, July 2018.
Presidential candidate Andres Manuel Lopez Obrador gestures as he addresses supporters after polls closed in the presidential election, in Mexico City, Mexico, July 2018.
Edgard Garrido / REUTERS

Moreover, several Mexican migration policies are in dire need of reform. Although the country has slightly more generous asylum laws than the United States, it has been overwhelmed by applications, and its immigration enforcement system—from detention centers to deportation procedures—operates with limited transparency and oversight. Mexico was also the co-convener with the United States of the Alliance for Progress, an international effort to fund economic and justice reforms in Central America, but these efforts too seem to have faltered.

This leaves U.S. policymakers with a choice. One option is to continue to criticize the Mexican government for not doing enough to stop Central American migrants on their way through Mexico before they reach the U.S. border and pressure it to do more. This has been the strategy of the Trump administration up until now, and it has had some limited success with the current Mexican government of President Enrique Peña Nieto, who was determined to save the North American Free Trade Agreement (NAFTA) and willing to entertain pragmatic deals across issue areas. The U.S. government even tried to get negotiations going with their Mexican counterparts on a “safe third country” agreement, which would require the Mexican government to be responsible for any migrants passing through its territory. 

But this strategy seems far less likely to work with a López Obrador administration, which will have a more nationalist bent and which will face far more public scrutiny for how it treats Central American migrants. So the other option is try to engage the new government of Mexico in a joint strategy that looks at Central American migration flows more comprehensively. That would have to include a willingness from U.S. authorities to help the Mexican government develop its immigration system by expanding asylum capacity and further professionalizing immigration enforcement to meet international standards. It would also have to include efforts to create integration programs for those Central Americans who choose to stay in Mexico and a renewed effort with regional partners through the Alliance for Progress to help El Salvador, Guatemala, and Honduras develop their police and judicial institutions to rein in gang violence, as well as generate some measure of economic development.

The status quo, in which the U.S. and Mexican governments have moved in tandem to stem the flow of Central American migration primarily through enforcement policies, is unlikely to continue. The family separation policies implemented in the United States have awakened greater public debate on this issue in Mexico, and the new administration seems likely to have priorities other than those of its predecessors, in part responding to this public pressure. This does not mean that the Trump and the López Obrador administrations cannot find common cause on migration issues but, rather, that they will have to do so in a way that recognizes that enforcement, asylum protections, professionalization of immigration agencies, and efforts to address root causes are all part of the same package.

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