The Pentagon has authorised a seven-month loan of its Active Denial System, the so-called “heat ray,” to the Department of Homeland Security for testing at the southern border, according to a memo from Defence Secretary Pete Hegseth reported by CNN. The system, which uses 95-gigahertz millimetre waves to create an intense burning sensation on skin, is designed to repel crowds without causing permanent injury.
The Active Denial System has been in development for decades but never deployed operationally. It projects an invisible beam that penetrates less than a millimetre into the skin, heating the surface enough to force anyone in its path to move away. The range extends beyond half a mile, allowing operators to target groups from a safe distance.
Why now
The loan reflects the administration’s search for new tools to manage the border, where large groups of migrants periodically gather at crossing points. Non-lethal crowd-control technology offers a middle path between doing nothing and using force, at least in theory. In practice, the history of such systems is fraught: the “heat ray” nickname alone guarantees controversy, and any deployment will face intense scrutiny from human rights groups and lawmakers.
The seven-month timeframe suggests an evaluation period rather than a permanent deployment. DHS will test the system’s effectiveness, safety and operational practicality, and the results will determine whether the concept advances or is shelved once again.
The technology debate
Directed-energy weapons sit at the uncomfortable intersection of innovation and ethics. Proponents argue they reduce harm by giving security forces options short of lethal force. Critics counter that “non-lethal” is a misnomer, that such weapons lower the threshold for using force, and that testing them on vulnerable migrant populations raises profound moral questions. The security-technology debate is covered in our earlier reporting, with more on the policy implications for federal agencies. CNN’s reporting has the memo’s details.
