In my column last month (tinyurl.com/4u9hrthz), I painted an admittedly dystopian picture of the U.S.-Mexico border in the relatively near future: a no-man’s land where American border agents use lethal force to repulse loosely organized groups of desperate migrants repeatedly scaling walls and barbed-wire fences and trying to use their numbers to overwhelm and escape the guards.

The moral crisis that America will be facing at that time will be the result of two converging trends: the drastic increase in the number of migrants fleeing the effects of climate change and the militarization of America’s southern border with the attendant “Fight the invaders!” belligerent discourse. We will wake up one day to images of border guards shooting at hundreds of migrants rushing a weak point in the border fortifications, and we will wonder how we got here, and, more importantly, whether we should just get used to living in a fortress whose impenetrability is maintained by periodic human sacrifices.

The migrants will not be an “invading” force then any more than they are now, for they will not carry arms and they will not aim to overthrow America’s government. But they will be desperate, and there will be many more of them than there are now, and they will use the tactics of the weak, including swarming. And the American border guards will not be any more bloodthirsty than they are now, but they will have been conditioned to act like soldiers and they will use their weapons to stop “infiltrations.”

How likely is this doomsday scenario? Pretty likely, unfortunately.

Climate change is ravaging many of the world’s regions that are already affected by poverty, violence and bad governance. According to the Geneva-based Internal Displacement Monitoring Centre, a record 32.6 million people around the world were chased out of their homes in 2022 by droughts, fires, floods, hurricanes, and crop failures due to bad weather. They say that by 2050, more than a billion people could be displaced just by climate-related calamities.

The rapid increase in the number of migrants is obvious everywhere, including Europe and the United States. Honduras, one of the top sources of U.S.-bound migrants, is currently traversing a period of alternating droughts and flooding, which is causing many of its subsistence farmers to pack up and head north. Given that the world is nowhere on track to meet the 2015 Paris Agreement climate change mitigation goals, these upheavals are almost certain to grow exponentially.

And meeting the incoming migrants is a U.S. border that has been increasingly treated as a war zone by the American authorities since the early 1970s. The Border Patrol, a division of the Department of Homeland Security, is armed to the teeth, with very little distinguishing it from the regular U.S. military. The border itself is being more and more fortified every year, with the Biden administration making the latest move in that direction earlier this month when they invoked executive power to build a new section of the wall.

The conditions are ripe for disaster.

When faced with borders bristling with razor wire, drones and radars, desperate migrants often use a tactic that gives individuals a chance of making it through the gauntlet and evading capture: rushing a small section of the border and hoping to be the one who gets to step foot on American soil, which is a prerequisite for claiming asylum.

We know how this works because we’ve seen it before. We’ve seen it in three iterations: light, moderate and God-awful.

In its “light” iteration, we’re seeing it now at the Mexico-U.S. border, especially in Texas, where, as The New York Times recently reported, “National Guard soldiers and state troopers patrol between lines of concertina wire, engaging in cat-and-mouse pursuits with migrants,” pushing them away and threatening them with guns. There have also been reports of shootings, and in 2018, hundreds of migrants were repelled with tear gas near the border crossing in Tijuana.

In its “moderate” iteration, we’ve been seeing the “treat onrushing migrants as invaders” dynamic in Spain’s enclaves in North Africa. Melilla and Ceuta are two medieval towns geographically situated in northern Morocco but fully under the jurisdiction of Spain, who took possession of them in 1497 and 1668, respectively. In the early 1990s, Spain started building fences on the towns’ perimeters to keep out migrants from sub-Saharan Africa.

As the number of migrants increased, so did the fortification of the borders. They now have rows of razor-wire fences 20 feet high, overlooked by hundreds of cameras and sensors. It is impossible to sneak into the towns. So the migrants attempt mass crossings in plain view of both Moroccan and Spanish border guards. Violent clashes ensue and many die.

The “God-awful” version of this dynamic has been on full display for the past two years at the Yemen-Saudi Arabia border where, according to the Human Rights Watch, Saudi border guards regularly shot and abused Ethiopian migrants fleeing violence and abject poverty.

How long before the Mexico-U.S. border moves from the “light” version to the “God-awful” version?

Conservatives often rightly point out that liberals are unwilling to give a straight answer to the questions, “Exactly how many migrants are we willing to allow in? And what do we do with the rest?”

But conservatives too rarely face up to the probable consequences of their own preferred immigration policies. When you’ve built the wall but desperate climate refugees keep scaling it and running past the border guards, how many men, women and children will you shoot at in order to maintain “law and order”?

Razvan Sibii is a senior lecturer of journalism at UMass Amherst. He writes a monthly column on immigration and incarceration. He can be contacted at razvan@umass.edu.