One of the pillars of the Mérida Initiative called for the “creation of a 21st-century border.” The construction of a wall which relies on state-of-the-art technology instead of a physical barrier has received bipartisan support within the United States Congress, both for its supposed effectiveness and affordability but also for being less controversial than a physical wall.


The first implementation of remote sensing technology at the border can be traced back to the “McNamara Line” named for former Secretary of Defense Robert McNamara, which used seismic, magnetic, and acoustic sensors repurposed from the Vietnam War. At the time of its implementation, much of the border was still unreinforced.