Mirror operations (operaciones espejo) are coordinated border security initiatives in which the US Department of Defense/Homeland Security and Mexico's SEDENA (Secretaría de la Defensa Nacional) and Guardia Nacional deploy synchronized patrols simultaneously on both sides of the Rio Grande. Neither nation crosses the International Boundary Line (IBL); instead, parallel movements close blind spots, discourage illicit crossings, and establish rapid mutual radio notification while honoring full sovereign boundaries.