A no-notice alert to deploy to the U.S. southern border gave the 10th Mountain Division the opportunity to test new equipment, build military-to-military relationships and gain real-world experience against a determined and adaptive adversary.

The U.S. military has supported U.S. Customs and Border Protection for years. While previous missions seemed to erode readiness as soldiers were employed as unskilled labor instead of highly trained maneuver forces, that is not the case today. Empowered by new authorities and a refined purpose, troops deployed along the southern border lead multidomain operations alongside the agency’s Border Patrol agents to protect the territorial integrity of the United States. It may be the same border, assisting the same partners, against the same adversaries, but this is a new mission.

In January 2025, the 10th Mountain Division headquarters at Fort Drum, New York, received a no-notice alert to deploy to the southern border and establish the core of a new joint task force assigned to U.S. Northern Command. Within days, lead elements of the 10th Mountain Division staff were dispatched along the border, with Fort Huachuca, Arizona, chosen as the site for the new joint task force headquarters. 

Complex Mission

The division’s task was to support Border Patrol to reduce instability resulting from cartel drug running, sex trafficking and human smuggling into the United States. The division headquarters brought unity of effort to one of the nation’s most complex and dynamic missions as additional troops from all services and components deployed to support the mission as Joint Task Force-Southern Border (JTF-SB).

JTF-SB became responsible for operating across the 1,954 miles of the U.S.-Mexico border, from San Diego to the Rio Grande Valley in Texas. Operations along the border spanned differing human and physical geography, including cities, deserts, mountains and overgrown riverbanks.  

The men and women of JTF-SB were committed to helping the Border Patrol detect, respond to and interdict illegal crossing activities along the southern border—on land, water or in the air. This meant synchronizing efforts across all domains—land, air, maritime, space, cyber and the electromagnetic spectrum.

One of the first efforts of JTF-SB was to realign military forces deployed to the border along the nine distinct Border Patrol sectors, from San Diego and El Centro, California, and Yuma, Arizona, in the west; to Tucson, Arizona, and El Paso and Big Bend, Texas, in the center; to Texas’ Del Rio, Laredo and Rio Grande Valley in the east.

Where one brigade used to span these sectors, JTF-SB now had enough forces to align battalions with each sector, partnering a battalion commander with each of the nine Border Patrol sector chiefs. The joint task force also integrated command posts at echelon where battalions, companies and platoons began conducting operations from the Border Patrol sector headquarters and many local station headquarters. JTF-SB and Border Patrol elements coordinated operations, analyzed intelligence and consolidated resources toward one purpose—gaining full operational control of the southern border.

The joint task force impacted the mission by leveraging its unique military capabilities. This included persistent surveillance, engineering, logistics, intelligence, targeting and employment of all-domain operations. 

The designation of cartels as foreign terrorist organizations, along with the declaration of a national emergency at the southern border, allowed JTF-SB to apply expanded authorities on the border. Units were able to lead mounted and dismounted patrols within their sectors and leverage their unique military capabilities against the foreign terrorist threats emanating from across the border.

Companies and battalions orchestrated deliberate maneuver operations against cartel smuggling lines, including air assaults, employing advanced counter-unmanned aircraft systems and electronic warfare systems. As a result, units within JTF-SB gained real-world experience in combined-arms maneuver against a determined and adaptive adversary. Regardless of service or component, units deployed to JTF-SB left more proficient at warfighting than when they arrived. Equipment operators, mechanics and pilots gained operational experience that is hard to replicate at home station.

Command System Tests

At the division level, the mission presented an ideal challenge to test mission command systems. It also drove innovation, enabling division headquarters to incorporate the Army’s Next-Generation Command and Control, artificial intelligence, machine learning, and data interoperability and to identify new methods to visualize the battlefield.

Extensive integration with federal, state, tribal and international partners operating on both sides of the border also was key to JTF-SB success. The U.S. Coast Guard and Border Patrol’s air- and maritime-

operations branch have become integral task force partners, providing critical capabilities, including riverine units, additional transport helicopters and fixed-wing reconnaissance aircraft. The Rio Grande river in South Texas became a critical region where riverine units from the Coast Guard and other federal partners offered unique patrolling capabilities for border security.

The joint task force also expanded military-to-military relationships with the Mexican military. Mexico’s northern frontier spans from Tijuana in the west to the mouth of the Rio Grande in the east. JTF-SB forces in each sector began organizing “trilateral” patrols where JTF-SB and Border Patrol elements conducted operations north of the border in coordination with Mexican troops south of the border. These patrols expanded in sophistication as partnerships grew.

The collective effects generated by partner integration on both sides of the border were unprecedented. To measure success, JTF-SB adopted Border Patrol’s key metrics, including established designations of detections, apprehensions, turn-backs and got-aways.

A detection occurred once an illegal crossing attempt was identified by any means or method, including camera systems, dismounted patrols, aerial patrols and static observation posts. A turn-back occurred when an illegal crossing attempt was aborted. Both turn-backs and apprehensions were recorded as positive outcomes for detections. Those who managed to avoid apprehension were designated as got-aways. Got-aways became the most objective measure to whether JTF-SB and Border Patrol achieved full operational control of the border. By every measure, the joint task force and Border Patrol continued to record fewer got-aways and more turn-backs and apprehensions over the first nine months of operations.

As the joint task force helped gain greater control of the border, the cartels were not going to simply abandon their multibillion-dollar business model of drug smuggling and human trafficking. They adapted, probed and adjusted their practices, shifting from one domain to another. Drone incursions from Mexico became increasingly prevalent along the border. The cartels employed sophisticated drone tactics that rivaled those of major rival states and adversaries abroad, using small drones, such as quadcopters, to help identify new smuggling routes, guide illegal crossings in real time or use payload-carrying drones to transport drugs by air.

Counter-Drone Tactics

This environment allowed the joint task force to test the effectiveness and functionality of counter-drone weapons and air domain awareness technology. The environment created a battle lab for the U.S. Army to experiment with transforming-

in-contact initiatives, an effort to put new technology into soldiers’ hands for testing and feedback.

JTF-SB began evaluating the performance of counter-drone sensors, developing data sharing and cross-domain solutions. This included developing artificial intelligence and machine learning programs to synthesize operational data collected from across the joint task force and Border Patrol.

JTF-SB also worked to integrate drone sensor and radar data across networks to form holistic drone defenses for maneuver forces—a key gap in which U.S. forces have little real-world combat experience.

The multitude of threats faced along the southern border also enabled JTF-SB to help drive important changes in homeland defense authorities and processes, including counter-drone protocols, that can be used to defend military installations and federal facilities nationally.

The mission remains more than just a border security effort—it builds warfighting readiness and prepares leaders to fight large-scale combat operations.

Yet, success at the border is measured not only in tactical outcomes. The strength of partnerships, the adaptability of formations and the professionalism of those involved are critical components to the mission’s success, as well.

Border security equals national security, and the men and women of the joint task force prove that steadfast service and collaboration make a measurable difference in defending the homeland.

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Maj. Gen. Scott Naumann is the commanding general of the 10th Mountain Division, Fort Drum, New York. Previously, he commanded Joint Task Force-Southern Border at Fort Huachuca, Arizona. He has deployed to Afghanistan and Iraq. He graduated in 1996 from the U.S. Military Academy, West Point, New York, and has a master’s in diplomacy and military studies from Hawaii Pacific University.

Lt. Col. D. Max Ferguson is the director of operations, G-3, for the 10th Mountain Division. Previously, he served as director of operations for Joint Task Force-Southern Border. He is a career infantry officer.