This is creating wide zones of “disorder” — and the biggest geopolitical trend in the world is all the people trying to get out of zones of disorder into the world of order. And that is what’s creating all the populist, nationalist, anti-immigrant backlashes in the world of order — particularly in America and Europe.

That is the real context for this immigration crisis. What’s the answer? Well, if you look at what slowed the flood of single Mexican men illegally and legally coming to America in the last decade, it was the combination of greater economic opportunity in Mexico, thanks in part to Nafta, plus slower population growth in Mexico, plus improved governance in Mexico, plus better border security along the Mexico-U.S. border.

That same formula has to be applied now to Guatemala, Honduras and El Salvador. They have become the primary source of all those migrants and caravans coming to America today, including 187,000 minors without adult guardians, who were picked up by the U.S. Border Patrol between 2014 and 2018. Their parents sent them our way to connect with relatives already here or to be shielded from forced gang recruitment and violence.

A report last June by the Council on Foreign Relations noted, “In 2015, the latest year for which data is available, as many as 3.4 million people born in El Salvador, Guatemala and Honduras were living in the United States, more than double the estimated 1.5 million people in 2000.” Because of rampant corruption and gang warfare, Salvadorans, Hondurans and Guatemalans each year pay an estimated total of $651 million in extortion to organized crime groups. These gangs, like MS-13, exploded in Central America in the mid-1990s “following large-scale deportations from the United States of undocumented immigrants with criminal records.”

That’s why, among other things, a smart U.S. immigration policy would promote family planning in rural areas in Central America. Letting America’s religious right limit U.S. family planning assistance abroad is stupid.

The only thing more stupid is not working to mitigate climate change, which Trump refuses to do. Extreme weather has been disrupting small-scale farming in Central America. And when small-scale farming weakens or collapses, people leave the countryside and flock to the city. And if they find high unemployment and high crime rates there, they head to America.

At the same time, we need an investment shock by local and foreign companies and governments to build infrastructure, tourism and trade in Central America so more people can thrive there, especially when 61 percent of the population is under 29 years of age.