Active duty troops’ authority to detain and search increased along southern border

Escalating immigration enforcement, President Donald Trump significantly expanded Biden-era policy of using National Guard troops at the US-Mexico border, as reported by Stars and Stripes. A sixty-foot-wide, 170-square-mile stretch of land along New Mexico’s southern border has been designated as part of Arizona’s Fort Huachuca, enabling active-duty troops to arrest individuals for trespassing on newly defined military territory.

Based on an executive order by President Trump, the Department of Interior is transferring the Roosevelt Reservation to DOD. Troops stationed under US Northern Command are now authorized to temporarily detain, search, and provide medical treatment to individuals crossing this militarized corridor. US military will also enforce crowd control, conduct patrols, and operate aerial and ground surveillance, according to Gen. Gregory Guillot, NORTHCOM commander. The Joint Task Force-Southern Border, which oversees the mission, may also request temporary barriers and fencing to maintain control.

Since October 2024, Border Patrol agents in New Mexico have encountered about 30,000 unauthorized migrants—down significantly from over 121,000 in the prior fiscal year. Officials credit Trump’s redeployment of active-duty troops for a steep drop in daily crossings, now averaging just 230 per day, compared to 5,100 under President Biden.

While the Pentagon maintains that troops will continue to support CBP, the newly granted powers raise fresh concerns about the militarization of immigration enforcement and the use of federal land for domestic operations. The implications for civil liberties and long-term precedent remain unclear.