**Recent setbacks in U.S.-Iran diplomacy, including stalled talks after the June 2026 memorandum of understanding and sharp divisions in the UN Security Council, underpin the 89.5% implied probability that no endorsing resolution will pass by December 31.** Negotiations for a final nuclear agreement have faltered amid renewed hostilities, U.S. strikes, sanctions disputes, and Iran's reported non-compliance with IAEA safeguards, prompting a September board referral to the Council. Russia and China have repeatedly vetoed U.S.-backed measures on monitoring and sanctions enforcement, while rejecting the legal basis for snapback provisions tied to expired Resolution 2231. With midterm elections approaching and persistent gaps over enrichment levels, verification, and sanctions relief, the timeline leaves little room for the consensus required for UNSC action.