Inside an armored vehicle, an army scout uses a joystick to direct a long-range optical scope toward a man perched atop the US-Mexico border wall cutting across the hills of this Arizona frontier community.
The man lowers himself toward US soil between coils of concertina wire. Shouts ring out, an alert is sounded and a US Customs and Border Protection SUV races toward the wall – warning enough to send the man scrambling back over it, disappearing into Mexico.
The sighting on Tuesday was one of only two for the army infantry unit patrolling this sector of the southern border, where an emergency declaration by Donald Trump has thrust the military into a central role in deterring migrant crossings at US ports of entry.
“Deterrence is actually boring,” said 24-year-old Sgt Ana Harker-Molina, giving voice to the tedium felt by some fellow soldiers over the sporadic sightings. Still, she said she takes pride in the work, knowing that troops discourage crossings by their mere presence.
“Just if we’re sitting here watching the border, it’s helping our country,” said Harker-Molina, an immigrant herself who came from Panama at age 12 and became a US citizen two years ago while serving in the army.
US troop deployments at the border have tripled to 7,600 and include every branch of the military – even as the number of attempted illegal crossings has plummeted and Trump has authorized funding for an additional 3,000 border patrol agents, offering $10,000 signing and retention bonuses.
The military mission is guided from a new command center at a remote army intelligence training base alongside southern Arizona’s Huachuca mountains. There, a community hall has been transformed into a bustling war room of battalion commanders and staff with digital maps pinpointing military camps and movements along the nearly 2,000-mile border.
Until now, border enforcement had been the domain of civilian law enforcement, with the military only intermittently stepping in. But in April, large swaths of the border were designated militarized zones, empowering US troops to apprehend immigrants and others accused of trespassing on army, air force or navy bases, and authorizing additional criminal charges that can mean prison time.
The two-star general leading the mission says troops are being untethered from maintenance and warehouse tasks to work closely with border patrol agents in high-traffic areas for illegal crossings – and to deploy rapidly to remote, unguarded terrain.
“We don’t have a [labor] union, there’s no limit on how many hours we can work in a day, how many shifts we can man,” said Maj Gen Scott Naumann of the army. “I can put soldiers out whenever we need to in order to get after the problem and we can put them out for days at a time; we can fly people into incredibly remote areas now that we see the cartels shifting” course.
At Nogales, army scouts patrolled the border in full battle gear – helmet, M5 service rifle, bullet-resistant vest – with the right to use deadly force if attacked under standing military rules integrated into the border mission. Underfoot, smugglers for decades routinely attempted to tunnel into stormwater drains to ferry contraband into the US.
Naumann’s command post oversees an armada of 117 armored Stryker vehicles, more than 35 helicopters, and a half-dozen long-distance drones that can survey the border day and night with sensors to pinpoint people wandering the desert. Marine Corps engineers are adding concertina wire to slow crossings, as the Trump administration reboots border wall construction.
Naumann said the focus is on stopping “got-aways” who evade authorities to disappear into the US in a race against the clock that can last seconds in urban areas as people vanish into smuggling vehicles, or several days in the dense wetland thickets of the Rio Grande or the vast desert and mountainous wilderness of Arizona.
Meanwhile, the rate of apprehensions at the border has fallen to a 60-year low.
Naumann says the falloff in illegal entries is the “elephant in the room” as the military increases pressure and resources aimed at starving smuggling cartels – including Latin American gangs recently designated as foreign terrorist organizations.
He says it would be wrong to let up, though, and that crossings may rebound with the end of scorching summer weather.
“We’ve got to keep going after it; we’re having some successes, we are trending positively,” he said of the mission with no fixed end date.
The Trump administration is using the military broadly to boost its immigration operations.
“It’s all part of the same strategy that is a very muscular, robust, intimidating, aggressive response to this – to show his base that he was serious about a campaign promise to fix immigration,” said Dan Maurer, a law professor at Ohio Northern University and a retired army judge advocate officer. “It’s both norm-breaking and unusual. It puts the military in a very awkward position.”
The militarized zones at the border sidestep the Posse Comitatus Act, an 1878 law that prohibits the military from conducting civilian law enforcement on US soil.
“It’s in that gray area. It may be a violation – it may not be. The military’s always had the authority to arrest people and detain them on military bases,” said Joshua Kastenberg, a professor at the University of New Mexico School of Law and a former air force judge.
Michael Fisher, a security consultant and former chief of the border patrol from 2010 to 2016, calls the military expansion at the border a “force multiplier” as border patrol agents increasingly turn up far from the border.
“The military allows border patrol to be able to flex into other areas where they typically would not be able to do so,” he said.
At daybreak on Wednesday in Arizona, Spc Luisangel Nito scanned a valley with an infrared scope that highlights body heat, spotting three people as they crossed illegally into the US, in preparation for the border patrol to apprehend them. Nito’s unit also has equipment that can ground small drones used by smugglers to plot entry routes.
Nito is the US-born son of Mexican immigrants who entered the country in the 1990s through the same valleys he now patrols.
“They crossed right here,” he said. “They told me to just be careful because back when they crossed they said it was dangerous.”
Nito’s parents returned to Mexico in 2008 amid the financial crisis, but the soldier saw brighter opportunities in the US, returned and enlisted. He expressed no reservations about his role in detaining undocumented immigrants.
“Obviously it’s a job, right, and then I signed up for it and I’m going to do it,” he said.
