At a fabrication site in Otay Mesa, one can see miles of barbed wire, rows of concrete roadblocks and countless bundles of rebar.
Together, the pieces will form reinforced barriers that Marines who have deployed to the border have been using to block lanes at the San Ysidro and Otay Mesa ports of entry.
More than 1,100 Marines have been deployed to assist U.S. Customs and Border Protection with Operation Secure line, a “border hardening” mission meant to prepare the area’s infrastructure for the arrival of thousands of people among the migrant caravan seeking asylum in the United States.
Thousands more troops from other branches have also deployed to the border to assist in other ways. For example, Army Military Police are there to protect the Marines who are not armed and are prohibited from enforcing the law. The Department of Defense insisted last week that the troops were sent there to help CBP and nothing else.
Analysts and the Pentagon estimate that the entire deployment operation could cost $200 million, maybe more, leaving some Americans to wonder if it’s a justifiable use of taxpayer money.
“As far as that question is concerned, I am not designed or able to answer that question because it’s not my place. My place is not to think about fiscal restraint, that’s for Congress. We’ve been asked to do a job and that’s what we’re here to do," Army Captain Guster Cunningham said.
CBP said the Marines' specific duties include installing barbed wire to make walls less scalable, and reinforcing construction areas so that people could not cross into them.
Another example of their work can be seen along the stretch of the border fence that separates Border Field State Park and Playas De Tijuana, Mexico.
Coils of concertina wire were strung along the top of the fence to deter caravan members who had climbed to the top of it to get a better look at their final destination.
In October, President Donald Trump threatened to close the southern border to address the caravan if the situation worsened. Since the arrival of the first troops at the border, CBP has acknowledged that option is still on the table.
CBP said it expects the waves of migrants in the most recent caravan to total more than 4,000 people.