The Justice Department on Friday issued a legal opinion concluding that American soldiers can arrest migrants just outside the militarized zones the Pentagon controls along the southern border, CBS News reported in a story updated Saturday morning [1]. The opinion comes from the Office of Legal Counsel, the office that tells the rest of the executive branch what the law permits, and it carries the signature of Deputy Assistant Attorney General William Hyde [1].
The operative sentence, as CBS quotes it, reads: "In sum, we conclude that the use of military personnel to arrest trespassers just outside of an NDA would not violate the [Posse Comitatus Act], given the express statutory authorization and the military-purpose of a commander's traditional protective power" [1].
NDA is the government's shorthand for a national defense area. CBS describes the zones as large swaths of land near the border with Mexico that the administration has designated for the purpose of deterring illegal immigration [1]. There are six so far, in Arizona, California, New Mexico and Texas, and Friday's opinion said the military has suggested it may designate additional zones in the future [1]. The military is generally prohibited from enforcing laws on domestic soil under the Posse Comitatus Act; the zones have been the mechanism around that prohibition, because soldiers guarding closed military land can detain the people who enter it [1].
The arrests are not an abstraction. The Justice Department began charging people apprehended in the zones in April 2025 and has charged hundreds more since [1]. The specific charges are most commonly two misdemeanors, violating a military security regulation and entering military, naval or Coast Guard property [1]. U.S. Northern Command, which oversees American military forces in North America, has said on its website that service members can apprehend people who trespass into a national defense area and transfer them to the appropriate law enforcement authorities [1].
Read the Hyde sentence again and notice where the weight sits: "just outside of an NDA." The detention authority the government has exercised since the spring rested on the military's control of its own ground. Friday's opinion extends the arrest power to people who are not on that ground. How far "just outside" reaches is a question the excerpts CBS published do not answer.
We tried to read the opinion itself and could not. The Office of Legal Counsel's pages on justice.gov refused our requests, and no direct link to the Hyde opinion had surfaced by publication time. Every characterization of the document in this piece rests on CBS's account of it [1].
An OLC opinion is not a court ruling, and no court has passed on this one. It is the executive branch advising itself, and agencies treat that advice as operative until a judge says otherwise. What that means in practice is concrete. A migrant near an NDA boundary in New Mexico or Texas now faces arrest by a soldier rather than a Border Patrol agent, followed by the kind of federal misdemeanor charges prosecutors have already filed by the hundreds [1]. The Posse Comitatus line between military power and civilian policing did not move by an act of Congress or a ruling from the bench. It moved by memo, over William Hyde's signature, on a Friday in August.
