Secretary of State Marco Rubio assessed that Supreme Leader Mojtaba Khamenei is "probably still alive" and "increasingly engaging at some level" 1, the first on-record US official read on the decision-making capacity of the man who holds the deal's nuclear and cash conditions. Mojtaba was installed in Iran's wartime succession on 7 March and has not appeared publicly since 8 March.
The back-channel Rubio described under oath runs on written-only couriers with a three-to-five-day lag. That lag caps how fast any remaining gap can close, and it means Washington is bargaining through a counterparty it cannot reach in real time and cannot confirm is making decisions. Iran has sent no counter-proposal on its highly enriched uranium (HEU) stockpile, the material enriched to 60 per cent that sits at the heart of the file, and Araghchi reported no progress on 4 June . The Soufan Center, a US security research group, noted on 1 June that Mojtaba's exact decision-making authority remains unclear 2.
The succession was disputed from the start: at least eight Assembly of Experts members boycotted the 7 March vote over his lack of theological credentials. The IRGC (Islamic Revolutionary Guard Corps), Iran's ideological military, holds the cash and nuclear conditions and has run the negotiating delegation since April, which means the civilian Foreign Ministry channel Washington is using may not be the channel that can actually commit Tehran. If the man who must sign is incapacitated or contested internally, the deal's final stretch rests on an authority the United States can neither see nor confirm.
