The Department of Defense (DoD) has a long history of supporting efforts to secure U.S. borders. Since the early 1990s, DoD has supported civilian law enforcement agencies’ border security activities including counterdrug, counter transnational organized crime, and other transnational threats. The scope and magnitude of the support provided today is similar to the support provided during the Bush, Obama, Trump and Biden administrations.
On Jan. 20, 2025, President Donald J. Trump, issued and signed an array of Executive Orders (EO) related to the Southern Border including a national emergency declaration at the Southern Border and clarification of the military’s role in protecting the territorial integrity of the United States. The national emergency EO directs the Department of Defense through U.S. Northern Command (USNORTHCOM), to take all appropriate action to assist the Department of Homeland Security in obtaining full operational control of the Southern border.
Over 10,000 service members are deploying / have deployed to the southern border to augment the approximately 2,500 service members already deployed supporting CBP’s southern border mission. The exact number of personnel will fluctuate as units rotate personnel and as additional forces are tasked to deploy once planning efforts are finalized.
Military personnel do not directly participate in civilian law enforcement activities. The active-duty personnel will support enhanced detection and monitoring efforts and repair and emplace physical barriers. Military personnel who have provided border security support as part of the FY2025 Department of Homeland Security request have performed to duties to include detection and monitoring, logistics, and transportation support that enhances CBP’s ability to impede or deny illegal crossings, maintain situational awareness, and apply the appropriate law enforcement response in support of its overall border security mission.
For imagery related to USNORTHCOM activities related to southern border operations, go to https://www.dvidshub.net/unit/DoDSWB25.
A National Defense Area is an area of operations on a military installation and is a specified area of Federal land which is under the administrative jurisdiction of DoD, which permits DoD to establish and enforce a controlled perimeter and control access to the area, just as it would on any other part of a military installation.
The Department of Defense has assumed administrative jurisdiction over specific Federal land on border areas to enhance the Department’s ability to protect the U.S. southern border from unlawful entry and to maintain the sovereignty, territorial integrity, and security of the United States. As with any military installation, the Department is preventing unauthorized access to the area through an appropriately identified, controlled perimeter and will deny unauthorized or unlawful entry, disrupt threats, and deter criminal activities.
Current NDAs:
New Mexico NDA
Totaling approximately 110,000 acres, the first NDA traverses non-contiguously from the Arizona and New Mexico state line eastbound to the New Mexico and Texas state line and ranges from 60 feet to one mile wide. This NDA is an annex of U.S. Army Fort Huachuca, AZ.
USNORTHCOM Press Release | Fort Huachuca Website
Texas NDA
The U.S. Section of the International Boundary and Water Commission (IBWC) temporarily transferred the jurisdiction of some federal property within a 63 mile stretch of land between El Paso, TX and Fort Hancock, TX to DoD. This NDA is an annex of U.S. Army Fort Bliss, TX.
USNORTHCOM Press Release | Fort Bliss Website | Map
Future NDAs:
South Texas NDA
The U.S. Section of the International Boundary and Water Commission (IBWC) temporarily transferred the jurisdiction of some federal property on and along an approximately 250-mile stretch of the Rio Grande River in Cameron and Hidalgo Counties (between South Padre Island (the mouth of the Rio Grande) and Roma, TX) to DoD. This NDA will be designated as part of Joint Base San Antonio under the jurisdiction of the Department of the Air Force.
Air Force Press Release
Yuma NDA
The Department of Interior temporarily transferred the jurisdiction of 138-miles of federal property along the U.S.-Mexico border adjacent to the Barry M. Goldwater Range to DoD. This NDA will be designated as part of Marine Corps Air Station Yuma under the jurisdiction of the Department of the Navy.
Pentagon Yuma NDA Statement
Questions and Answers
Q. What is DoD doing in the National Defense Areas?
A. Within the designated NDAs, DoD will conduct operations in support of protecting the southern border, as directed by the President in Executive Order 14167, “Clarifying the
Military’s Role in Protecting the Territorial Integrity of the United States.” DoD will establish and enforce a controlled perimeter and controlled access to the NDA to repel unlawful mass migration, narcotics trafficking, migrant smuggling, human trafficking, and other cross-border criminal activities.
Q. Can the DoD arrest people in the NDAs? Including U.S. citizens?
A. As with any military installation, this land is under DoD’s administrative jurisdiction. This includes the authority to prevent unauthorized access and to detect and deter potential security threats to maintain security, order, and discipline, which may include apprehending those who enter without authorization. Any person apprehended for trespassing (or committing other criminal offenses) on a military installation, regardless of citizenship, will be transferred over to appropriate non-DoD law enforcement officials as promptly as practical. As an example: A gate runner who breaches a military base may be apprehended by military personnel and transferred to local law enforcement custody for additional processing; it will be
no different within the NDAs.
Q. If an immigrant is apprehended by DoD troops, where will they be held and under what authorities?
A. As with any military installation, this land is under a commander’s jurisdiction. This includes the authority to prevent unauthorized access and detect and deter potential security threats to maintain security, order, and discipline, which may include apprehending those who enter without authorization, regardless of citizenship. There is no intention for the military to detain trespassers for any significant period of time. Those apprehended for trespassing (or committing other criminal offenses) on the military installation or NDA, and anyone apprehended, would promptly be transferred to appropriate non-DoD law enforcement officials.
Relevant Links
April 11, 2025: Presidential Action - Military Mission for Sealing the Southern Border of the United States and Repelling Invasions
April 11, 2025: Memorandum on the Military Mission for Sealing the Southern Border of the United States and Repelling Invasions
Border Operations
Operational Support
Service members providing motor transport operations support increase vehicle readiness rates. Military personnel dispatch vehicles, track preventative maintenance checks and services, and conduct light maintenance such as oil changes, tire changes, and battery replacements on CBP vehicles. DoD personnel may also operate heavy equipment such as forklifts, bulldozers, graders and front-end loaders to support sector/station loading and unloading of palletized shipments and infrastructure duties.
Detection and Monitoring Support
Service members supporting the CBP’s detection and monitoring mission man and operate mobile surveillance camera (MSC) vehicles at strategically placed sites to observe and report suspicious activity to CBP. MSC operators are working in Arizona, California, New Mexico and Texas along known corridors used by individuals illegally entering the United States. Military members are only utilized to detect and monitor movement of individuals suspected of preparing to enter the United States, or those who have already entered the United States without proper authority.
Crisis Response Force (CRF) Support
Service members supporting the CRF are capable of providing force protection, medical, aviation and engineering support anywhere along the border on short notice. The CRF is made up of an aviation unit, a military police unit, engineer unit, inherent medical capabilities, and associated support personnel for these units. The CRF is activated upon CBP request.
Air Support
DoD aviation support missions include tracking foot traffic signs, pickup/drop off of CBP agents in remote areas, monitoring for illicit activity, casualty evacuation, sling load capability, and transport of equipment as needed.
USNORTHCOM works closely with DHS and CBP to constantly assess support to CBP to ensure DoD has the right force, at the right time, in the right location to support CBP’s operational needs.
Q1. (U) What is USNORTHCOM’s role as it relates to President Trump’s Southern Border Security Executive Order? 
Q1. (U) USNORTHCOM is DoD’s operational lead for the employment of U.S. military forces to carry out President Trump’s Executive Orders on protecting the territorial integrity of the United States. The command is being supported by relevant DOD Combatant Commanders, Military Departments, and the National Guard Bureau, all of which are working in conjunction with the Department of Homeland Security and Customs and Border Protection to secure the border
Q2. (U) Is this part of the border mission currently conducted by USNORTHCOM?
A2. (U)The President’s Executive Order directs a new and different mission. The initial surge of ~1,500 served to immediately increase the capacity of support to established CBP-support missions, but the size, composition, capabilities, and mission of the forces along the southern border will change.
Q3. (U) If DHS and CBP are the lead agencies for border security, why is the military needed?
A3. (U) USNORTHCOM has provided support at the southern border, through requests by DHS, for roughly 20 years. Our presence at the border is not new. However, USNORTHCOM has been directed by Executive Order to provide more support at the border, and that is what we’re doing. A primary mission of USNORTHCOM is homeland defense, and the President has said the federal government must act with urgency and strength to end the threats posed by an unsecured border. We are aggressively carrying out the Command in Chief’s orders to augment DHS and CBP efforts there to achieve full operational control of the southern border.
Q4. (U) Will more military troops be going to the border?
A4. (U) The initial number of military personnel recently sent to the southern border is about 1,600, and an additional 500 from 10th Mountain Division and 140 from the Joint Force will be joining the southern border mission. As we continue to enact the President’s Executive Order, we anticipate additional personnel will be tasked for support in the future. It’s too early to comment on what those are and what that looks like. The Department of Defense and USNORTHCOM is actively planning and assessing the situation to ensure we are postured to meet all requirements and needs at the border. As planning continues to evolve, we will provide updates and information as necessary to keep the public informed.
Q5. (U) How long will active-duty members be sent to the southern border to support this mission?
A5. (U) The President’s EO stipulates that efforts will be ongoing until complete operational control of the southern border is achieved.
Mission
Joint Task Force-Southern Border (JTF-SB) conducts full-scale, agile, and all-domain operations in support of Department of Homeland Security (DHS) to secure the U.S. southern border, disrupt transnational criminal organizations, and respond to national security threats.
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For imagery related to JTF-SB activities, go to DoD Southern Border 2025
Media Relations / Public Affairs
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