Trader consensus on a U.S. invasion of Mexico in 2026 remains near-certain due to sustained bilateral security cooperation, including recent joint exercises along the Rio Grande targeting cartel networks, ongoing USMCA review talks, and Mexico’s explicit rejection of foreign troops on its soil as a red line. President Sheinbaum’s government has expanded its own counternarcotics efforts while U.S. actions stay limited to designations of cartels as foreign terrorist organizations, intelligence sharing, and border-zone enforcement expansions. Deep economic interdependence through trade, supply chains, and migration flows further raises the costs of any large-scale military operation. Constitutional requirements for congressional authorization and the absence of mobilization or war declarations reinforce the barrier. Late-year developments such as a major cartel incident prompting unilateral strikes or a sudden breakdown in diplomatic channels could still shift probabilities before year-end.