The Pentagon has authorized the Department of Homeland Security (DHS) to test a military-grade heat ray for possible use along the US-Mexico border. The move opens a new chapter in the Trump administration’s efforts to expand immigration enforcement technology.

But the weapon, designed to drive away people through an intense burning sensation, comes with difficult questions about safety, legality, and whether it is necessary at all.

According to CNN reporters Zachary Cohen and Priscilla Alvarez, a memo signed by Defense Secretary Pete Hegseth last month permits DHS to borrow the weapon for seven months, beginning in September 2026.…