Enrique Acevedo is an anchor for the late-night edition of “Noticiero Univision” and a special correspondent for the Fusion Media Group.

Donald Trump campaigned in his 2016 presidential bid with a central promise: He would build a “great, beautiful wall” along the southern border to stop undocumented immigrants from “pouring” into the country. And Mexico would pay for it.

Recently, under pressure from Washington, Mexican President Enrique Peña Nieto stepped up to fulfill part of Trump’s campaign pledge when he ramped up security at the border with Guatemala to stop a caravan with thousands of Central American migrants, including women and young children.

Members of the caravan defied Mexican authorities’ entreaties for an orderly crossing in a dramatic bid to breach the border, but were met by a phalanx of hundreds of federal police officers in full riot gear, armed with shields and pepper spray. The travesty that ensued will be remembered as a low point in Mexico’s otherwise humanitarian tradition welcoming refugees.

But in the end, Mexico’s shameful response and Trump’s extreme policies, including family separation, have been no match for the sea of humanity that has joined the caravan since it left Honduras two weeks ago. Migrants are determined to come to the United States.

It would be more constructive to ask ourselves not why these people are coming to our country, but rather, why they are leaving theirs. The American public needs to recognize that the largest factor driving immigrants into the United States is not a weak, unprotected border.

The United States spends more money each year on border and immigration enforcement than the combined budgets of the FBI, the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the Drug Enforcement Administration (DEA), the Secret Service and the U.S. Marshals Service combined, according to a report by the Migration Policy Institute. More than 20,000 agents are deployed in the southern border with all-terrain vehicles, helicopters, boats, drones and military-grade surveillance equipment to patrol what has become one of the most guarded areas in the planet.

Most undocumented immigrants now come from Guatemala, Honduras and El Salvador, not Mexico. This includes an increasing number of women and children, who turn themselves in at the border and request asylum to survive the violence they face back home — violence fueled in no small part by the drug consumption in the United States and its so-called war on drugs to combat the cartels that supply the U.S. market. The refugees are leaving behind their homes to embark on a journey out of necessity, not opportunity.

Heidi Torres, who celebrated her 15th birthday on the caravan while traveling with her 3-month-old baby, told Univision reporter Maity Interiano recently that the alternative for her and her son back home was a life of violence and criminality. “I don’t want that for my child,” she said. “I want my baby to have a future.”

Meanwhile, Trump presents himself as the game-changer on immigration,  but all he has done is double down on the same failed policies of the past. Rather than viewing enforcement as part of a broader strategy, it has become the only strategy. And instead of focusing more resources on mitigating the root causes of immigration, we keep trying to stop immigrants once they show up at the door. It has never worked, and if Trump follows through on his threat to cut foreign aid to Central American countries, then he will only exacerbate the immigration problem he has bet his political brand on fixing.

U.S. assistance has played a key role in the efforts to reduce crime and violence in Central America. President Barack Obama’s Central America Regional Security Initiative (CARSI) provided more than $1 billion in aid to help reform law enforcement, the justice system and governance structures. In 2014, USAID published an assessment of its community-based programs that targeted dangerous neighborhoods in Honduras, El Salvador and other countries. The assessment showed significant drops in the reports of murder, extortion and drug sales.

Our broken immigration system won’t be solved by bumper-sticker rhetoric, placing more armed guards at the border or by building a 2,000-mile wall. Any real, long-term solution requires a serious plan to work with countries in the region and local communities in eradicating or minimizing push factors, such as violence and extreme poverty.

We are facing an unprecedented humanitarian crisis and all the governments involved should act accordingly. Coercive measures are only making things worse. We have a choice: We can either spend a little there to make a big difference at our border, or keep spending untold billions of taxpayer dollars here to make no difference at all.