**Deep-seated disagreements over sequencing of concessions, nuclear limits, and sanctions relief have stalled U.S.-Iran negotiations following the collapse of the June 2026 Islamabad MOU.** That interim accord aimed to end hostilities, reopen the Strait of Hormuz, and produce a final nuclear agreement within 60 days for UN Security Council endorsement, yet talks broke down amid disputes on uranium enrichment, inspections, and blockade relief. In September and October 2026, Iran’s seven-condition proposal for Hormuz reopening drew an insufficient U.S. response, while the IAEA Board referred Iran to the UNSC for safeguards noncompliance, a step opposed by Russia and China. Snapback sanctions remain in effect, Resolution 2231 disputes persist, and P5 divisions block consensus. With the December 31 deadline approaching amid mutual distrust and threats of renewed military action, traders assign a 90% probability that no endorsing resolution will pass.