The Active Denial System (ADS) “heat ray” mounted on the back of a truck. The Pentagon has loaned the ADS to the Department of Homeland Security for border control, according to new reports. (US Air Force)
The Department of Homeland Security Is Testing a ‘Heat Ray’ at the Southern Border
The “Active Denial System” is a non-lethal weapon, but the ethics of using it to deter migrants seeking to enter the United States are debatable nevertheless.
The concept of aliens from outer space armed with “heat rays” has its origins in the HG Wells novel The War of the Worlds, first published in 1898. The weapon later became a common trope in the wave of science fiction films released in the 1950s, in which men from outer space turned them against the human race.
Now, the United States is testing a real military-grade heat ray along the southern border to stop a different type of alien: migrants crossing the southern border in violation of existing US immigration law.
Secretary of Defense Pete Hegseth has approved a seven-month loan of the Pentagon’s “Active Denial System” (ADS) to the Department of Homeland Security (DHS), which could potentially deploy the weapon along the US-Mexico border, CNN first reported.
Although the authorization doesn’t clarify how it could be used, or even if it will be deployed, Patrick Weaver, deputy chief of staff to the Secretary of Defense, responded to the CNN report, writing on X, “The border is now a military installation and a battle lab for testing new systems, to include directed energy weapons. The border is locked down!”
US military personnel will not operate the ADS while it is on loan to DHS, so DHS agents will develop the tactics, techniques, and even procedures on how to use the system. Discussion has largely centered on employing it to disperse crowds at the southern border.
The ADS Is Not a “Death Ray”—but It Does Hurt
Unlike its War of the Worlds counterpart, the ADS isn’t a “death ray,” but rather a “nonlethal weapon.” It shoots an invisible beam of electromagnetic waves with a range of around half a mile, and has a starting temperature of around 111 degrees F, roughly the temperature of a very hot shower. CNN wrote that “the energy beam causes a burning sensation when it comes into contact with the human skin.”
This isn’t exactly new technology. Development of the ADS began in the late 1990s. Two active systems were built and later evaluated under the Pentagon’s Defense Advanced Concept Technology Demonstration (ACTD) program, with it being publicly revealed in 2007.
“The Active Denial System will support a full spectrum of operations ranging from non-lethal methods of crowd dispersal, checkpoint security, perimeter security, area denial, port protection and infrastructure,” the DoD explained in a fact sheet on a now-archived website.
The DoD fact sheet further stressed that the ADS was not a laser weapon. It noted that some “adverse reactions” could occur, particularly skin blisters, but stressed that these were “extremely rare.”
The weapon was reportedly deployed to Afghanistan, but was never used in any combat operations. There were also discussions as to whether it could be employed in crowd control at overseas detention facilities. DHS had even considered utilizing the ADS during the first Trump administration, but it was never deployed.
“The issue was treating immigrants and citizens like enemy combatants,” a former DHS official told CNN. “Thematically, inhumane treatments typically get rejected.”
But times change, and the second Trump administration has been clear that it views immigration as its top issue. Hegseth and DHS Secretary Markwayne Mullin have signaled a readiness to take a much harder line in stopping the flow of migrants at the southern border than their predecessors.
Is It Ethical to Use a Heat Ray on Border Crossers?
Within Customs and Border Protection (CBP), there is also doubt over the need for the ADS, as border crossings are low.
Still, a group consisting of hundreds of migrants from Central America, as well as from Ecuador and Haiti, departed from San Pedro Sula, Honduras, on September 20, 2026, and crossed into Mexico. Known as Fe y Esperanza con Dios (Faith and Hope with God), it has been traveling largely on foot toward the US border. Some media outlets in the United States have characterized the group as a “migrant caravan,” while others have disputed that description.
Whether DHS could use the ADS to disperse the group isn’t clear, but they could include it among the tools at the ready.
Technology industry analyst Roger Entner, founder of Recon Analytics, told The National Interest that the DHS’ interest in the weapon likely came from its desire to break up the crowd without causing permanent harm—a tricky balance that law enforcement agencies have often struggled to meet.
“DHS is trying to find non-lethal weapons instead of using lethal weapons,” Entner wrote in an email. “Hurting people and making them change their ways without killing them is the entire point.”
However, Andrew Coville, a United States Marine Corps veteran who was deployed to both Iraq and Afghanistan before serving as a police officer in the Yarmouth Police Department in Massachusetts, questioned whether such technology should be tested by the DHS in the field against unarmed civilians.
“We risk treating those individuals as enemy combatants,” Coville warned in an email to The National Interest. “Even if the system is intended as a tool of deterrence, its safety must be established beyond a reasonable doubt before we risk inflicting serious harm on another human being.”
About the Author: Peter Suciu
Peter Suciu regularly writes about military hardware, firearms history, cybersecurity, politics, and international affairs. He has contributed to dozens of newspapers, magazines, and websites over a 30-year career in journalism, including Forbes and Clearance Jobs. He is based in Michigan. You can follow him on Twitter: @PeterSuciu. You can email the author at Editor@nationalinterest.org.
The post The Department of Homeland Security Is Testing a ‘Heat Ray’ at the Southern Border appeared first on The National Interest.