In February 2018, U.S. border agents took a four-month-old baby from his father, who was deported overseas. Last May, a 16-year-old boy died from influenza after being held in a detention processing facility in McAllen, Texas. Earlier this month, a transgender migrant died hours after being paroled from custody.

As more unaccompanied minors and other asylum-seekers arrive on the southern border, alarming accounts continue: reports of rotten food causing illness, kennel-style fences holding migrants in El Paso, Texas, and another facility in the same city holding more than six times its capacity of detainees. This week, the Department of Health and Human Services announced that it would handle the influx of unaccompanied minors by housing some of them at Fort Sill, an Army base in Oklahoma that held detainees of Japanese descent during World War II, a bleak reminder of another time when America failed to live up to its values.

Beyond each individual crisis, we should ask, what are these places? Are they refugee camps, or are they something else? History provides the answer.

People today tend to think of Nazi death camps as defining the term “concentration camp.” But before World War II, this phrase was used to describe the detention of civilians without trial based on group identity. During a rebellion in Cuba in 1896, the Spanish Empire swept rural peasants—mostly women and children—off the land. Declaring them a threat, Spanish forces held them behind barbed wire in fortified cities. Around 150,000 people died. Three years later, America opened its own concentration camps for women and children as part of an effort to suppress a revolt in the Philippines during the Philippine-American War.

Around the globe in southern Africa, the British government opened its own concentration camps in the new century, embracing civilian detention as a civilizing force for an “uncultured” people. Unsanitary camp conditions and inadequate food triggered medical crises. By the time the British moved to address the disaster they had created, it was too late for many detainees. Tens of thousands of children died.

These camps opened and closed in different settings but never vanished from the face of the earth. In southern France during the Spanish Civil War, hundreds of thousands of refugees fled across the border, ending up in camps without sanitation or food. In Myanmar in 2012, more than a hundred thousand Rohingya Muslims were segregated into camps that left the community vulnerable to ethnic cleansing years later.

Today’s U.S.-Mexico border camps are the heirs of these concentration camps. Putting people in similar conditions will unleash illness and death. The more people who are detained, the larger these crises will become.

By the time a country gets to the point that those in power and a majority of their supporters embrace policies that back up virulent rhetoric and accept detention as the central response to a political or humanitarian problem, it is very difficult to undo.

From its first days, the Trump administration has mouthed dehumanizing rhetoric about migrants. On the day Trump announced his candidacy, he fired his opening salvo against Mexicans, and, as president, he has only continued in the same vein about all migrants crossing the southern border. Setting up measures like a weekly immigrant crime report during the first weeks of the administration, the White House underlined the president’s antagonistic approach.

In a tweet on Monday night, Trump wrote about plans for the U.S. Immigration and Customs Enforcement agency to initiate mass immigration arrests and removal: “Next week ICE will begin the process of removing the millions of illegal aliens who have illicitly found their way into the United States. They will be removed as fast as they come in.” While the scope of deportation that Trump is threatening appears to be unlikely given current resources, attempts at mass deportation typically cause additional detention crises, in transit camps and at transportation sites charged with moving detainees. This operation will only further degrade the system.