When a crowd is exposed to tear gas, an aerosol containing the chemical agent 2-chlorobenzaldene malononitrile (CS), nasal passages begin to run, eyes water uncontrollably and breathing grows short and painful. Those directly exposed can experience vomiting or diarrhea. Effects take hold within 30 seconds, and the symptoms can last up to 10 minutes, even after the air has cleared or the afflicted have managed to scramble to safety.

For these reasons, nearly every nation in the world banned the compound’s use in warfare under the Chemical Weapons Convention of 1993. Yet despite ratifying these agreements, the United States continues to utilize tear gas for domestic riot control. Police shot dozens of canisters at protesters over several days in Ferguson, Mo., and now U.S. Border Patrol agents have fired upon Central American migrants and their toddlers in Tijuana, Mexico, seeking asylum in the United States—an act of aggression that almost certainly violates international law.

When President Donald Trump announced that he would be deploying soldiers to the southern border, in numbers that seemed to swell in direct proportion to the fever of his campaign rallies, the media eagerly enabled his hysteria, treating the arrival of a few hundred refugees as an impending alien invasion. And while Nicholas Kristof has since acknowledged that The New York Times allowed itself to be manipulated ahead of a midterm election, few appear willing to confront the darker reality this assault has laid bare: The Trump administration has sought to militarize the region from the start.

In January of 2017, mere days after Trump was sworn into office, Bloomberg published a report detailing Magal Security Systems’ offer to construct the president’s long-promised wall. (Shares in the company soared 50 percent following the 2016 presidential election.) During a conference on border security, the company presented its Fiber Patrol product to officials from the U.S. Department of Homeland Security, among others. Previously, Magal Security Systems had constructed Israel’s border wall with Gaza, as well as a fence separating the country from Egypt.

While a physical wall will likely go unfunded with Democrats now controlling the House of Representatives, the president has nonetheless achieved its central aim. By separating children from their migrant parents at the border, the Trump administration has exerted its dominance over a vulnerable population, and signaled to its supporters that it will not simply accept white nationalism as a byproduct of American empire but embrace it as a matter of public policy. As of October, administration officials had failed to reunite hundreds of these children with their mothers and fathers, months after a court-imposed deadline to do so.

In recent weeks, the U.S. military has laid down miles of concertina barbed wire along the U.S. border with Mexico as part of Operation Faithful Patriot. Secretary of Defense Jim Mattis has since dropped the name of the mission on the grounds that it was too military sounding; when asked if the troops planned to remove the wiring, he replied, “We’ll let you know.”

It seems increasingly unlikely. During a recent stop in Montana, Trump gushed over the work of the U.S. military along the border, the new tracts of fencing in particular. “Mexico is trying, they are trying but we’re different, we have our military on the border,” he said. “And I noticed all that beautiful barbed wire going up today. Barbed wire, used properly, can be a beautiful sight.”

If decades of U.S. foreign policy have shaped the migrant caravan, from President Ronald Reagan’s violent maneuverings in Nicaragua and El Salvador during the waning days of the Cold War to Secretary of State Hillary Clinton’s assistance in the Honduran coup of 2009, the crisis currently unfolding in Tijuana is almost entirely of the Trump administration’s making. “Trump’s border policy has squeezed asylum seekers at both ends,” observes Vox’s Dara Lind. “Officials stress that migrants ought to present themselves legally at ports of entry, while asylum seekers at ports are forced to wait days or weeks for entry to the US, and President Donald Trump himself says they shouldn’t be coming at all.”

For the president and his enablers, that a refugee’s method of entering the country has no bearing on his or her claims to asylum is ultimately irrelevant. As is so often the case in this administration, the cruelty is the point. Trump has since threatened to shut down the Mexican border “permanently,” an act of dubious legality that, coupled with acts of violent suppression, would only further Gaza-fy the southern border. This was the idea all along.