On 22 October 2026, the Pentagon authorised the Department of Homeland Security (DHS) to test an Active Denial System (ADS) for possible use along the US–Mexico border. A memo signed by US Defense Secretary Pete Hegseth in September 2026 permits DHS to borrow one unit for seven months, starting in September.
Active Denial System
The ADS is a directed-energy system that emits an invisible beam of electromagnetic energy. The beam heats the skin’s surface and creates an intense burning sensation without physical contact. Its intended effect is to make people move away from the beam; the sensation typically lasts 10 to 15 minutes. The system has a reported range of slightly more than half a mile.
The US military briefly deployed the ADS to Afghanistan nearly two decades ago, but it was not used in combat. US officials also considered the system for crowd control at facilities abroad holding terrorist detainees, but did not proceed with that use.
Testing and operational oversight
The DHS request did not identify a testing location or specify how the system might be used in future border operations. DHS is responsible for operating the unit and developing its tactics, techniques and procedures. The memo excludes Department of War personnel from operating the system. DHS may request a further period of use after the initial seven-month loan.
Customs and Border Protection officials examined the technology in the El Centro sector, which covers about 70 miles of the US–Mexico border. In 2018, the agency considered using the ADS against migrants, but then-Homeland Security Secretary Kirstjen Nielsen rejected the proposal.
Safety and legal considerations
Potential concerns include the system’s effectiveness, legality and risk of harm. People moving away from the beam could enter dangerous areas or water, creating a risk of indirect injury and a possible need for rescue operations. Earlier discussions included whether the system could discourage crossings near a river or move people out of the water.
Important Facts for Exams
- The Active Denial System uses electromagnetic energy to produce a surface-heating sensation without physical contact.
- The system is designed to make people move away from the beam, and its reported range is slightly more than half a mile.
- The US military deployed the ADS to Afghanistan but did not use it in combat.
- Customs and Border Protection is a US federal agency within the Department of Homeland Security.
The temporary loan authorises testing, while the testing location and any eventual border deployment remain unspecified. DHS is responsible for operating the system during the authorised loan period.
