WASHINGTON (AP) – A recent decision by President Donald Trump has resulted in the transfer of a long stretch of federal land along the U.S.-Mexico border to the Department of Defense. This area will be administered by the Army as part of an Army installation, raising concerns that military troops could detain unauthorized individuals, including migrants, who trespass on this land. U.S. officials informed The Associated Press of this new development.
The move to bring the border zone under military control appears to circumvent federal laws that restrict the deployment of U.S. troops for domestic law enforcement purposes. While the Posse Comitatus Act prohibits military involvement in such activities, an exception known as the military purpose doctrine could allow for it if the primary mission is non-law enforcement related. However, experts suggest that this rationale will likely face legal challenges, as the intent behind transferring the Roosevelt Reservation to the military is clear—to enhance border security.
The Pentagon is currently reviewing the implications of this land transfer. However, the current aim of the Trump administration is to allow military personnel to detain migrants crossing unauthorized into U.S. territory. The National Security Council has not yet provided any commentary on the matter, indicating a degree of uncertainty surrounding the administration’s legal standing.
The Roosevelt Reservation, a 60-foot-wide federal buffer zone that stretches along the border from New Mexico to California, has historically been managed by the Interior Department. This recent presidential memo indicates a shift in control, now placing the area in the hands of the Defense Department. Following this, for a 45-day trial period, the Defense Department will test control over a section of the Roosevelt Reservation located in New Mexico, east of Fort Huachuca Army installation in Arizona. During this period, the Army plans to erect additional fencing and post signage warning against trespassing.
Reports suggest that anyone unauthorized in the newly designated Army-controlled area could face arrest by military security personnel. This raises critical questions about the potential interactions between military units and unauthorized migrants, as military personnel are expected to transfer any detained migrants to local civilian law enforcement agencies.
As of now, approximately 7,100 active-duty troops are stationed along the U.S.-Mexico border under federal command, in addition to about 4,600 National Guard troops operating under state authority. Despite existing regulations, there is an expectation that the military may not need to deploy additional forces due to this land reassignment, although specific operational details remain unclear.
Legal experts, such as Elizabeth Goitein from the Brennan Center for Justice, emphasize that the military purpose doctrine might not apply in this context. Troops deployed in the border area would need to demonstrate that their primary mission does not involve law enforcement duties related to border security, which contradicts the stated goal of the administration to tighten border controls. The legal complexities surrounding this transfer and its implications for military involvement in domestic law enforcement are expected to be points of contention in upcoming court challenges.
Rebecca Santana contributed from Washington.
