Ongoing diplomatic engagement and security cooperation between the United States and Mexico, including joint efforts against fentanyl trafficking and cartel activity, underpin trader expectations against a U.S. invasion in 2026. Tensions over tariffs, USMCA review, migration, and water deliveries have prompted threats of unilateral action or limited strikes, yet these pressures have channeled into negotiations and Mexican concessions rather than military deployment. Deep economic integration, respect for sovereignty, and congressional oversight further constrain escalation. Realistic shifts could arise from a sudden collapse in bilateral results on drug flows or a major border crisis, though institutional, legal, and strategic barriers would still need to align for any invasion scenario to gain traction.