A migrant mother and child wait for a northbound freight train in Salto del Agua, Chiapas state, Mexico, on June 24. (Marco Ugarte/AP)

Rising public concern about the humanitarian crisis at the border highlights the challenges the United States and Mexico face in trying to stem the tide of migrants traveling north. Although the presidents of the U.S. and Mexico recently shook hands on an agreement to curb migration and avoid tariffs, the likelihood of success is uncertain.

Here is what you need to know about the deal.

1. Mexico offered more manpower to tackle the crisis.

Mexico promises to deploy 6,000 national guard members to the Belize and Guatemala border. One thousand more authorized agents will be sent to the Suchiate and Usumacinta municipalities of the southern border. On the northern border, Mexico agreed to work with the United States to expand the Migrant Protection Protocols, also referred to as “Remain in Mexico,” and to provide asylum seekers with education, shelter and jobs. The Mexican government also deployed about 15,000 troops to its northern border, although this was not part of the original agreement.

2. The United States made important promises to Mexico but hasn’t yet ponied up.

Mexico dodged President Trump’s threat to impose tariffs on imports from Mexico, the U.S.’s top trading partner. That was Mexico’s most obvious benefit from the deal. Mexico could also benefit from a U.S. commitment to speed adjudication of migrants’ asylum claims, which might reduce the number of asylum seekers gathering at the U.S.-Mexico border.

Mexico is spearheading a Comprehensive Development Plan, which aims to reduce migration in the region by improving socioeconomic conditions in Guatemala, El Salvador and Honduras. The plan is a key priority for Mexico, which the United States has stated it will welcome.

But the U.S. government has not yet announced the steps it will take to speed up the resolution of asylum claims. Nor has the administration been specific about what reduction in migration levels would put tariffs permanently off the table. What’s more, the United States stated vaguely that it “welcomes” Mexico’s development plan but has made no offer to contribute financially. Nor is the Trump administration providing resources to ensure asylum seekers receive basic services and humanitarian assistance.

3. Mexicans favor tougher borders but are mixed on the deal.

Mexican public opinion polls suggest Mexicans support greater enforcement. Three-quarters of Mexicans in a recent poll believe migrants who enter Mexico illegally should be deported; two-thirds support militarizing Mexico’s southern border. Still, Mexican opinion about the deal is mixed. About 40 percent of Mexicans recently polled believe Mexico caved to U.S. demands, in part because Mexico appears to have committed to much more than the United States.

4. Many doubt the deal can succeed.

It’s not clear whether Mexico’s national guard can perform immigration functions or detain and deport enough people to satisfy the United States. A rush to send authorities to the border without proper training could lead to human rights abuses, as when Mexican police shot and killed a 19-year-old Salvadoran migrant woman last week.

Mexican border cities are unprepared, and Mexican citizens are wary of having to provide asylum seekers with shelter, jobs and education for months or years. Migrants face dire conditions such as overcrowded shelters, disease outbreaks and no apparent prospects for work.

5. Increased enforcement won’t necessarily deter migrants.

New evidence suggests that migrants are growing fearful of Mexican authorities. Swift detention and deportation at Mexico’s southern border sends the message that it will be more difficult to enter Mexico and pass through undetected.

But stronger enforcement can also increase the demand for smugglers who can help migrants desperate to flee their home countries’ conditions. Migrant smugglers are innovative and adaptable, which can make them hard to track and apprehend.

This has happened before. After Mexico increased its immigration enforcement in 2014, fewer migrants at first sought entry to Mexico. But in 2015 and early 2016, apprehensions at the U.S.-Mexico border began to creep back up as migrants found ways to avoid immigration agents in Mexico. In 2017, both Mexican and U.S. authorities apprehended the lowest numbers of migrants in years — registering just over 5,000 in Mexico, a significant drop from the 16,000 stopped the year before. But that’s probably because of U.S. government rhetoric, not beefed-up enforcement.

In December 2018, Mexico’s new president, Andrés Manuel López Obrador, oversaw a restructuring of the National Migration Institute, reducing the number of immigration agents. In January and February, the new Mexican government introduced more migrant-friendly policies, and the number of migrants apprehended dropped again. When it resumed enforcing restrictions on migration in February, apprehensions went up again.

6. Can Mexico be a “safe third country”?

Mexico agreed to consider making itself a “safe third country” if it cannot stem the tide of migrants. According to U.N. standards, a country so designated has agreed to keep asylum seekers safe from removal to their home countries; has a functioning asylum system; and treats asylum seekers in accordance with recognized basic humanitarian standards, such as shelter and safety.

The U.S. has a safe third country agreement with Canada, meaning that refugee claimants are required to request protection in the first safe country they arrive in, unless they qualify for an exception. But Mexico’s homicide rates, impunity for crimes and presence of criminal organizations raise doubts about whether Mexico would meet such standards.

What’s more, Mexico is cutting its asylum processing agency budget, even though it already struggles to keep up with the asylum claims. If Mexico signed onto such a deal, the number of claims would probably overwhelm the agency.

Guatemala is also in talks with the United States to sign a safe third country deal. But Guatemala’s institutional capacity is more limited than Mexico’s. Shifting the burden to Mexico (or Guatemala) will not ensure a safe or effective asylum process. U.S.-sponsored extraterritorial processing centers, where migrants can apply for asylum in the United States from designated safe zones, might work better to share the burden without overloading asylum systems or putting migrants in precarious situations.

Signing the deal has given Mexico a brief respite from U.S. threats. But if Mexico can’t keep its promises, the consequences are unclear. The number of migrants traveling to and through Mexico may well go down in the next month, as often happens in the summer — but could well go up again come fall. That suggests Mexico — again threatened with tariffs — could find itself right back at the negotiating table before long.

Don’t miss anything! Sign up to get TMC’s smart analysis in your inbox, three days a week.

Rachel Schmidtke (@r_schmidtke) is the program associate for migration at the Mexico Institute of the Woodrow Wilson International Center for Scholars.