U.S. Marines build border fence barriers near San Diego, California, on January 31, 2025, in response to the U.S. government’s emergency declaration, sealing off the frontier between the two nations. THE ASSOCIATED PRESS
The U.S. has deployed more than 2,500 troops to the Mexico-U.S. southern border since President Donald J. Trump issued a national emergency declaration in January 2025. At least 15 active-duty units from the U.S. Army and Marine Corps have been activated to “support enhanced detection and monitoring efforts and repair and emplace physical barriers,” according to a January 24 news release from U.S. Northern Command (USNORTHCOM). The Soldiers and Marines are mostly drawn from military police and combat engineer units. “Whatever is needed at the border will be provided,” U.S. Defense Secretary Pete Hegseth said January 27 in a Joint Task Force North news release. “The Defense Department will support the defense of the territorial integrity of the United States of America’s southern border, including reservists, National Guardsmen and active-duty [personnel] in compliance with the Constitution and the laws of our land, and the directives of the commander in chief.”
The new troop deployments bolster a force of about 2,500 National Guardsmen and other personnel already at the 3,145-kilometer frontier, which stretches through rough, arid terrain from California to Texas. The military is tasked with securing the border and stemming the flow of illegal migrants and drugs, particularly fentanyl. The troop surge will also enhance security at the U.S. military base in Guantanamo Bay, Cuba, which has been designated as a holding area for detained migrants, according to The Associated Press. The U.S. Air Force and other military planes have been used to transport illegal migrants back to their home countries. USNORTHCOM is coordinating the effort, which is still taking shape.
USNORTHCOM announced on February 4, 2025, that elements of Headquarters and Headquarters Battalion, 10th Mountain Division, from Fort Drum, New York, have been assigned to the command to support the border mission. About 500 members of the 10th Mountain Division will form the Joint Task Force Headquarters, the location of which remains to be determined, according to a USNORTHCOM news release. In addition, 140 intelligence personnel from the Joint Force have been assigned to USNORTHCOM to provide full motion video analysis, counter network analysis and Spanish language translation to the U.S. Border Patrol Office of Intelligence, the release stated. USNORTHOM also has created a Joint Intelligence Task Force-Southern Border “to integrate and deconflict intelligence planning and threat analysis to support USNORTHCOM’s effective employment of the Joint Force in protecting the territorial integrity and sovereignty of the United States,” according to the release.
The practical effects of this deployment are already visible. Marines are installing concertina wire at high-priority spots along the border, the AP reported. And more military activity is expected as the U.S. government has designated Mexican cartels, which control most of the migrant crossings and drug smuggling along the border, as foreign terrorist organizations and specially designated global terrorists, according to President Trump’s January 20, 2025, executive order. “The Cartels functionally control, through a campaign of assassination, terror, rape, and brute force nearly all illegal traffic across the southern border of the United States. In certain portions of Mexico, they function as quasi-governmental entities, controlling nearly all aspects of society. The Cartels’ activities threaten the safety of the American people, the security of the United States, and the stability of the international order in the Western Hemisphere. Their activities, proximity to, and incursions into the physical territory of the United States pose an unacceptable national security risk to the United States,” the order stated.