Sustained bilateral security cooperation between the United States and Mexico has anchored trader consensus against a U.S. invasion in 2026. Joint operations with U.S. intelligence support have produced major cartel disruptions, record fentanyl seizures, and measurable declines in border crossings and overdose deaths, while Mexican President Claudia Sheinbaum has repeatedly rejected unilateral military action on sovereignty grounds. Rhetoric from U.S. officials about strikes against cartels has not progressed to troop deployments, congressional authorizations, or other operational steps that would signal escalation. Deep economic ties under USMCA and institutional preferences for coordinated enforcement over direct intervention further reinforce the low implied probability. A sharp deterioration in partnership or a major cross-border security crisis could still introduce volatility before year-end.