The Administration’s actions at the southern border: Some observations
No doubt you’ve heard about the President’s latest move to secure the southern border by putting a strip of land along the border under the jurisdiction of the Department of Defense thus making it subject to military installation rules. Last week a journalist asked me about the President’s actions to seal the southern border and, specifically, how they might differ from his first term. I’ll relate to you some of what I told that reporter – and add in some extra notes for Lawfire® readers.
Context
According to DoD: “Soldiers…conduct a dismounted squad patrol outside of Sierra Blanco, TX, Mar 31. 2025”
On Inauguration Day 2025, the President, using the authority granted him in the National Emergencies Act of 1976, declared a “national emergency” at the southern border as a result, he said, of an “invasion” occasioned by “[o]ur southern border [being] overrun by cartels, criminal gangs, known terrorists, human traffickers, smugglers, unvetted military-age males from foreign adversaries, and illicit narcotics that harm Americans, including America.” He added:
“Because of the gravity and emergency of this present danger and imminent threat, it is necessary for the Armed Forces to take all appropriate action to assist the Department of Homeland Security in obtaining full operational control of the southern border.”
He went on to direct the construction of physical barriers and the use of unmanned systems.
The latest Presidential Proclamation about the border
More recently (Apr 11, 2025) the President issued another proclamation (“Military Mission for Sealing the Southern Border of the United States and Repelling Invasions”) wherein he took what I described as “an unorthodox but not necessarily illegal approach to using the military to help secure the border.” Here’s some more of what I said (with additional comments):
The President has declared securing the border to be a “military mission” and directed the transfer to the Department of Defense of a 60-foot wide strip of Federal land that extends along the border through three states. It seems that the Pentagon will then turn this land, called the Roosevelt Reservation, into what is, in essence, a narrow but very long military base. This was not done during the first Trump administration.
What does 60 feet equate to? Well, it’s just shy (by six inches) of the distance from the pitcher’s mound to home base for professional, high school and college baseball.
Land along the southern border is already used by DoD, the Department of Homeland Security and the Department of the Interior, but this action calls for DOI and DHS to cede their jurisdiction of this approximately 170-mile long (noncontiguous) land area to DoD. A DoD news release says this area would be considered an extension of Ft. Huachuca in Arizona after the Army accepts jurisdiction. Ft. Huachuca is best known for its focus on intelligence, training and cybersecurity.
The Presidential Memorandum specifically notes that this move would exclude any “Federal Indian reservations.”
The memorandum also states that the:
“Secretary of Defense may determine those military activities that are reasonably necessary and appropriate to accomplish the mission assigned in Executive Order 14167 and that are necessary to protect and maintain the security of military installations, consistent with section 2672 of title 10, United States Code, and the longstanding authority of a military installation commander to exclude persons from a military installation, as recognized in section 21 of the Internal Security Act of 1950 (50 U.S.C. 797) and 18 U.S.C. 1382.
Use of force
Furthermore, it states that “members of the Armed Forces will follow rules for the use of force prescribed by the Secretary of Defense.” Presumably, they would not be the rules of engagement employed for combat situations, but rather those provided for “DoD personnel performing security and protection, law and order, investigative, or counterintelligence duties; and for personal protection when related to the performance of official duties.“
Though Federal law generally prohibits the military from enforcing the law domestically, it has long been accepted that the military can temporarily detain for delivery to civilian law enforcement authorities those who trespass onto a military base non or who otherwise are suspected of breaking the law on the installation. This authority does not require an invocation of the Insurrection Act or even a declaration of a national emergency.
Challenged in the courts?
It is possible that the involvement of the military in securing the border could be challenged in the courts. Traditionally, the courts have been deferential to the elected branches of government with respect to military matters. Though that deference has arguably waned, I still believe it is unlikely that the courts will, in this particular instance, second-guess a President’s determination that securing the border is a military mission or where a military “base” might need to be established (or expanded) on government land.
Detentions by the military on the military base
According to DoD: “Soldiers organize boxes of clothing for illegal aliens in the Rio Grande Valley Sector Processing Center in McAllen, TX, Mar 18, 2025”
As a practical matter, I would be surprised if many people are actually detained by the military in the narrow albeit long military base. Rather, I expect that the overwhelming majority of the military will be involved in supporting civilian law enforcement, not detaining border-crossers.
However, with securing the border now being an explicitly declared military mission, and the creation of a military “base” along the border, there may be greater emphasis on utilizing military equipment and expertise to surveil the border and transmit the information obtained to civilian authorities to help track and apprehend illicit border-crossers.
In addition, the presence of armed troops and Stryker combat vehicles could well be a deterrent to those seeking to unlawfully enter the U.S., as well as to those engaged in human trafficking and drug smuggling.
Concluding thoughts
Given the dramatic decline in border crossings, I would not expect a significant increase in the number of troops deployed beyond the approximately 10,000 currently serving there.
Although Congress could intervene and possibly further limit the military activities at the border beyond existing law, I don’t sense there is much of an appetite to try to do so since a large majority of the public appears to approve of this use of the armed forces.
Remember what we like to say on Lawfire®: gather the facts, examine the law, evaluate the arguments – and then decide for yourself!
