US-Iran diplomatic relations remain severed since the 1979 Islamic Revolution and embassy hostage crisis, with Washington maintaining only a virtual embassy and relying on Switzerland as protecting power. A brief June 2026 memorandum of understanding and ceasefire after months of direct conflict collapsed weeks later amid renewed strikes, sanctions enforcement, and disputes over nuclear limits, the Strait of Hormuz, and proxies. As of September 2026, the Trump administration continues economic and military pressure, issues Level 4 travel warnings for Iran, and shows no movement toward restoring full diplomatic facilities in Tehran. Traders price the near-certain “No” outcome on these entrenched barriers and lack of scheduled normalization steps before year-end. Late breakthroughs at the UN General Assembly or a verified permanent accord addressing enrichment and sanctions could still shift probabilities, though such developments remain absent from current reporting.