US Army to Control Land on Mexico Border as Part of New Base: Potential for Migrant Detention Raises Legal Questions

by Derek White

In a bold move by the Trump administration, a federal land corridor along the U.S.-Mexico border is being transferred to the Department of Defense, with the U.S. Army set to take control of the area as part of an Army base. The land, which has long been a buffer zone, could now be used for security purposes, including the potential detention of migrants, according to U.S. officials.

The Roosevelt Reservation, a 60-foot-wide corridor stretching from New Mexico to California, was previously managed by the Interior Department. However, the Trump administration issued a memo on Friday directing the transfer of control to the Defense Department, which would give the Army the authority to enforce security measures and detain trespassers—potentially including migrants who cross into U.S. territory unlawfully.

The move is a direct attempt to bypass the Posse Comitatus Act, a federal law that generally prohibits U.S. troops from engaging in domestic law enforcement. The administration argues that if the land is designated as part of an Army installation, the military could perform security duties without violating this law. However, experts on presidential powers are raising concerns, with some predicting that the move will likely face legal challenges.

The plan is still under review by the Pentagon, but according to officials, the administration’s intent is to use military personnel to detain migrants along the border. In the coming weeks, the Defense Department will test this arrangement by controlling a section of the Roosevelt Reservation in New Mexico. During this trial period, the Army will erect additional fencing and warning signs, and unauthorized individuals found on the land could be arrested by military security forces.

While the military would be able to detain migrants under this plan, any individuals apprehended by troops would be transferred to local civilian law enforcement agencies, according to the officials. The military’s current role at the border has mainly consisted of supporting U.S. Customs and Border Protection through surveillance and administrative tasks, as well as providing backup for border wall construction and deportation operations.

The legality of the land transfer and the proposed military involvement in border security could spark significant legal challenges. Elizabeth Goitein, an expert in presidential emergency powers at the Brennan Center for Justice, explained that the military purpose doctrine—a legal exception allowing the use of troops for domestic purposes in certain situations—might not apply in this case. She argued that the primary mission of the military on this land would be to enforce border security, which could conflict with the law's provisions.

As the administration moves forward with the plan, the impact on military resources and potential legal ramifications remain uncertain. With thousands of active-duty troops already deployed to the border, it’s unclear if additional forces will be necessary to secure the newly designated area. The coming weeks and months will likely reveal whether this plan survives legal scrutiny and how it affects the ongoing debate over U.S. immigration and border security.