Trump campaign aims for greater military role in border security

Former President Donald Trump has made border security a cornerstone of his re-election campaign. If he wins in November, he will implement a series of new policies to deter the record-high border crossings of recent years.

According to his campaign platform, some of that policy could also include the U.S. military.

If elected, Trump says he will “use whatever means necessary to stop the invasion — including moving thousands of troops currently stationed abroad to our own southern border.”

It’s not yet clear whether Trump is referring to deploying the National Guard to border regions — an action presidents of both parties have taken to help U.S. Customs and Border Protection when border crossings are high — or whether he wants to redeploy active-duty troops currently stationed abroad to more homeland security-focused roles, which would be a more significant policy shift.

Trump’s campaign has also pledged to deploy the U.S. Navy to combat fentanyl smuggling and mobilize military resources against Mexican drug cartels.

For Trump’s supporters, the proposals are part of a broader shift toward an “America First” foreign policy that prioritizes protecting the homeland over involvement in foreign conflicts. They are also a necessary step in the fight against the illegal drug trade that has killed tens of thousands of Americans.

“President Trump will prioritize — I think he will always put America first,” said Tom Homan, who served as acting director of Immigrations and Customs Enforcement during the last Trump administration and is now a fellow at the Heritage Foundation, a conservative think tank with ties to Trump. “It doesn’t mean you take assets out of Ukraine or you take assets out of other places around the world. I think we have enough assets, but if it requires a reallocation of assets to protect this country, then that absolutely has to happen.”

Deployment of the National Guard

If elected, Trump will likely continue to deploy National Guard troops and even a small number of active-duty troops to the border, a move that both Democratic and Republican presidents have taken to increase Department of Homeland Security resources in the region.

Trump’s Defense Department in 2018 authorized up to 4,000 National Guard troops to support the Department of Homeland Security’s border mission amid a “drastic increase in illegal activity at the southern border.” Later that year, the administration sent up to 800 active-duty troops to bolster National Guard troops already present.

And President Joe Biden in 2023 announced plans to send 1,500 active-duty troops to the border, on top of the 2,500 National Guard troops already deployed at the time, in preparation for the rollback of border restrictions caused by the pandemic.

DOD personnel sent to the border do not perform law enforcement functions, but rather fill administrative roles to free up CBP agents for field work. Active-duty service members cannot perform law enforcement duties in the U.S. unless specifically authorized by Congress.

“So what DOD can do, what the military can do, is take those non-law enforcement tasks,” Homan said. “Take those tasks away from the Border Patrol, which allows more law enforcement to do exactly what they’re supposed to do, which is law enforcement and arrest and detain.”

The Defense Department’s involvement at the border in support of DHS has been common during recent administrations, but if Trump plans to redeploy large numbers of active-duty troops from overseas deployments to the border, that would be more controversial, said Carrie Cordero, a senior fellow at the Center for a New American Security who previously served on the Homeland Security Advisory Council.

“If the concept is to pull active-duty military personnel who are deployed overseas on military assignments and assign non-National Guard, full-time active-duty military personnel to the southern border, that would be a very different problem,” she said.

She noted that withdrawing troops from overseas missions has foreign policy implications and that deploying large numbers of active-duty troops for civilian law enforcement poses legal complications.

However, Katherine Kuzminski, director of the Military, Veterans, and Society Program at CNAS, said, “It is much more likely that Trump would want to send National Guard troops to the U.S.-Mexico border on a smaller scale than he would transfer active-duty troops from overseas deployments.

“I think the most likely scenario is using the Guard — not necessarily moving troops overseas,” she said. “But I think it makes good political sense for him to say he’s going to bring troops home from another country because it fits into a broader non-interventionist policy portfolio.”

Fighting cartels

Other Trump policy proposals involving the military in border security are less unprecedented and could present additional challenges, experts say.

Deploying the U.S. Navy to combat fentanyl trafficking would complicate the efforts of the U.S. Coast Guard, which is normally responsible for such activities.

“The Navy can call upon the Coast Guard to assume Title 10 authority in a time of war, but you don’t normally see the responsibilities go the other way, with the Navy supporting the Coast Guard,” Kuzminski said.

And militarily targeting criminal organizations involved in drug trafficking could jeopardize the U.S. diplomatic and economic relationship with Mexico or divert resources from other counterterrorism missions.

“In terms of the economic relationship with Mexico and the nature of the relationship between the countries, treating the cartels as terrorist organizations would be a major, major change in the way the United States conducts policy,” Cordero said.

However, using military force to take on cartels is not a new idea, and there is some support for it in Congress. In 2023, Reps. Daniel Crenshaw (R-Texas) and Michael Waltz (R-Fla.) introduced a bill that would authorize the use of military force to take on Mexican drug cartels that are “facilitating the fentanyl crisis.”

“We cannot allow heavily armed and deadly cartels to destabilize Mexico and import people and drugs into the United States,” Crenshaw said in a statement at the time. “We must start treating them like ISIS — because that is who they are.”

Other Republican candidates for elected office in recent years have echoed these calls; Florida Governor Ron DeSantis pledged during his presidential campaign to send special forces to Mexico to combat drug cartels.

“The bottom line is that the Mexican cartels have killed more Americans in Mexico than all the terrorist organizations in the world combined,” Homan said. “They are a threat to our national security. There is clear danger to this country.”

Congress approach

Republicans in Congress have increasingly taken a broader view of the Defense Department’s role in protecting the U.S.-Mexico border. The Senate version of the fiscal year 2025 defense authorization bill — which passed the committee on a bipartisan basis in June — includes several provisions that would direct Pentagon resources to certain border security activities.

The bill would increase information sharing between the Defense Department and federal, state and local authorities stationed along the southwest border, authorize the Pentagon to enter into service contracts to support CBP, and appropriate an additional $25 million for Joint Task Force North to combat transnational criminal organizations in the region.

“The effort to control the border should rightly be led by the Department of Homeland Security, but the Department of Defense can provide resources and assistance to support DHS when needed,” Sen. Roger Wicker, R-Miss., a member of the Senate Armed Services Committee, said in a statement. “DOD should also provide select resources for intelligence and information sharing, deploy certain DOD personnel, and increase coordination with other federal agencies.”