Recent changes in global migration patterns and smuggling routes have created an opening for terror groups like the Islamic State to set their sights on the U.S. southern border.
For years, top U.S. counterterrorism officials have pushed back against critics who sounded alarms about would-be terrorists streaming across the U.S. border with Mexico. But changes within the past year have increased the likelihood of such a reality.
"What we face today is a greater vulnerability to the possibility that terrorist organizations might use that pathway to get individuals into the United States," according to Nick Rasmussen, the counterterrorism coordinator for the Department of Homeland Security, or DHS.
"The diversity of the migrant population arriving at our borders — this is not in any way, shape or form a problem of the Western Hemisphere," Rasmussen told a conference Thursday in Omaha, Nebraska.
"It's a global migration problem with migrants from literally every corner of the world, including from most conflict zones around the world, showing up and arriving on our shores," he said, describing the convergence of the migration routes with concerns about terror groups like Islamic State "relatively recent."
Concerns about possible infiltration by migrants linked to the Islamic State, also known as IS or ISIS, have spiked in recent weeks.
Earlier this month, The New York Post reported the FBI arrested eight men from Tajikistan who crossed the U.S.-Mexico border partly with the help of an IS-linked network.
And earlier this week, NBC News reported more than 400 immigrants from Central Asia crossed into the U.S., again with help from IS-linked smugglers. Of those, some 150 have been arrested, while another 50 remain at large. The officials did not comment on the status of the remaining 200.
Senior DHS officials say there is no evidence to suggest any of the 400 Central Asian migrants are IS operatives.
But officials have said the eight men from Tajikistan were arrested because of potential ties to IS. All eight are in the middle of removal hearings and face deportation.
U.S. officials have sought to allay concerns.
White House deputy homeland security adviser Jen Daskal told the counterterrorism conference in Omaha on Wednesday that there is now increased vigilance along the U.S. southern border.
"We have enhanced our screening and vetting, instituted recurrent vetting of migrants to identify newly uncovered threats and detain those who pose a public safety threat," Daskal said. "We know that there is a continued risk posed by those inspired by these terrorist organizations, and we are acutely focused on that risk."
Rasmussen, speaking a day later, likewise pushed back against fears of a terrorist free for all.
"Most of the last decade there have been political critics who have said that terrorists are streaming across the southern border, and we could look at that analytically as our intelligence and law enforcement really did, and say, no, that's actually not happening," he said. "I would argue it's not true today, as well."
Rasmussen agreed, though, the newfound focus by groups like IS on exploiting migration to the Western Hemisphere deserves immediate attention.
The convergence of migration patterns and terrorism is "probably highest on my worry and priority list today," he said.
