Pentagon lets DHS test heat ray weapon for possible use at US border

The Pentagon has authorised the Department of Homeland Security to test a military-grade “heat ray” and develop tactics for its potential use in operations at the southern US border, according to a memo signed by Defence Secretary Pete Hegseth last month and obtained by CNN. (https://www.cnn.com/2026/10/21/politics/heat-ray-weapon-dhs-pentagon?cid=external-feeds_iluminar_meta)

The weapon, officially known as the Active Denial System, fires an invisible beam of electromagnetic waves that can reach a little more than half a mile away. The beam causes an intense burning sensation on the skin, which Pentagon officials have likened to opening a hot oven, with military officials saying the resulting “tingling effect” lasts between 10 and 15 minutes. (https://www.geo.tv/latest/687672-us-approves-use-of-heat-ray-weapon-at-mexico-border-that-makes-people-feel-their-skin-is-burning)

The memo authorises the “temporary loan” of one ADS unit for seven months, starting in September, and states that it “shall not be operated by DoW personnel”, placing responsibility for the system’s employment and the development of tactics on DHS. The DHS request did not specify where or how the system would be tested, and a defence official told CNN that DHS can request an extension after the loan period. (https://www.cnn.com/2026/10/21/politics/heat-ray-weapon-dhs-pentagon?cid=external-feeds_iluminar_meta)

Deployment at the border would be unprecedented. The system was briefly deployed to Afghanistan nearly two decades ago but was never used in combat, and in 2018 then-Homeland Security Secretary Kirstjen Nielsen rejected a proposal to use it against migrants. A Customs and Border Protection spokesperson said the agency “is continually evaluating new technologies, especially those that enhance operational effectiveness and strengthen mission capabilities”. (https://www.cnn.com/2026/10/21/politics/heat-ray-weapon-dhs-pentagon?cid=external-feeds_iluminar_meta)