Persistent adversarial relations since the 1979 Iranian Revolution and embassy seizure have left the United States without formal diplomatic ties or a physical embassy in Iran, reinforced by decades of sanctions, nuclear disputes, and proxy conflicts. Recent 2025–2026 negotiations and the Iran war produced ceasefires and memoranda on issues such as the Strait of Hormuz but yielded no movement toward diplomatic normalization or embassy reopening. Security alerts through mid-2026 continue to classify Iran as a Level 4 travel destination, reflecting ongoing risks. Traders assign a 95.5% probability to no reopening in 2026 because these structural barriers and active hostilities show no sign of rapid resolution. Late-stage breakthroughs in current talks, major de-escalation, or unexpected regime shifts could still shift the outcome before year-end.