The Pentagon announced on Wednesday that it has begun deploying up to 1,500 active-duty troops to reinforce security along the US-Mexico border, marking a significant step in the Trump administration’s efforts to address immigration and border security. This deployment follows the executive orders signed by President Trump shortly after his inauguration, which aimed to strengthen the US’s southern border against illegal immigration and transnational crime.
Acting Defence Secretary Robert Salesses confirmed that military aircraft would be utilised to support the Department of Homeland Security (DHS) in deporting over 5,000 detained migrants. The troops will also assist with the construction of border barriers as part of the administration’s broader efforts to enhance border security.
“This is just the beginning,” Salesses stated, hinting that the number of troops and the scope of their mission could evolve. While the Pentagon has yet to decide whether these forces will engage in law enforcement duties, which would be a major shift from their traditional role, this potential change raises concerns about the involvement of US military personnel in domestic civilian matters. Under the Posse Comitatus Act, US troops have been prohibited from performing law enforcement duties, although this law may be reconsidered should the Insurrection Act, dating back to 1807, be invoked. This law could permit military personnel to assist in civilian law enforcement during periods of civil unrest.
The deployment of active-duty troops will join the approximately 2,500 National Guard and Reserve forces already stationed along the 3,219-kilometre border. This brings the total number of military personnel at the border to more than 4,000. The first wave of active-duty personnel began arriving at the border on Wednesday, with 500 Marines from Camp Pendleton in California, and the remainder consisting of Army troops. These personnel are expected to carry out duties such as providing logistical support, constructing barriers, and helping the Border Patrol in their ongoing efforts to monitor and secure the region.
The US military has frequently been called upon to assist the Border Patrol, especially in response to large caravans of migrants or surges in border crossings. However, the Trump administration’s decision to deploy more active-duty forces to the border marks a notable expansion of the military’s role in homeland security. This is part of a broader strategy that also includes Trump’s commitment to building a wall along the southern border—a campaign promise he has continued to push during his presidency.
While troops have previously been deployed to assist in border security under both Trump and former President Joe Biden, the extent of their involvement in law enforcement remains a subject of debate. During the 2018 migrant caravan crisis, Trump ordered the deployment of more than 7,000 active-duty troops to Texas, Arizona, and California. These troops provided support in a variety of ways, such as transporting Border Patrol agents, constructing barriers, and offering medical assistance.
However, no troops were permitted to engage in law enforcement activities, as military personnel are restricted from doing so under the Posse Comitatus Act. The current deployment, like the one in 2018, is expected to follow a similar pattern, with troops assisting the Border Patrol in logistical and non-combat roles. It is still unclear, however, whether the Trump administration will extend the use of military bases as temporary housing facilities for detained migrants, as had occurred during previous administrations.
The US has faced significant challenges in dealing with large numbers of migrants at the southern border, with the Border Patrol often struggling to keep up with the demand for processing and detention space. With the number of migrants seeking refuge in the US on the rise, the involvement of military personnel may become an increasingly prominent feature of the border security landscape.
In addition to addressing migration, the deployment is part of a broader strategy to combat drug trafficking and organised crime in the region. With the military’s capabilities, including surveillance and logistical support, the Trump administration aims to disrupt the operations of transnational criminal organisations operating along the border.
As the US continues to grapple with immigration issues and border security challenges, the role of the military in domestic affairs is likely to remain a contentious issue, particularly regarding the scope of its involvement in law enforcement. The coming months will reveal the extent of this involvement and the impact it will have on US domestic policy regarding immigration.