The high implied probability against a U.S. invasion of Iran before 2027 reflects the ongoing pattern of limited air and missile exchanges, sanctions enforcement, and naval pressure since major combat operations began in February 2026. Intermittent strikes have continued into September amid a war of attrition, but U.S. actions have focused on degrading Iranian missile, naval, and nuclear-related capabilities rather than committing ground forces for occupation or regime change. Multiple ceasefire frameworks and a June memorandum of understanding collapsed without producing a ground operation, while administration statements emphasize economic isolation and verifiable nuclear constraints over large-scale troop deployments. Analysts note that a full invasion would require far more resources and carry greater risks than current approaches, with no verified shift toward that threshold in recent weeks.