U.S. Justice Department expands military power to detain migrants

The U.S. Department of Justice has issued a legal opinion expanding the authority of military personnel to detain migrants accused of trespassing in designated ‘National Defense Areas’ along the U.S.-Mexico border.

Under the opinion from the Office of Legal Counsel, military personnel may now arrest individuals who exit these restricted zones before they can be apprehended for trespassing. This expansion aims to support the administration’s border enforcement strategy in areas controlled by the Department of Defense. The Justice Department maintains that this does not violate the Posse Comitatus Act, citing express statutory authorization and the military purpose of protective powers.

Currently, six National Defense Areas have been established across Arizona, California, New Mexico, and Texas. Since the implementation of these charges in April 2025, hundreds of individuals have been charged, primarily with misdemeanors related to violating military security regulations. The Pentagon has indicated that additional zones may be designated in the future.