Iran and six world powers — the U.S., China, Russia, Britain, France, and Germany — have 29 days left to hammer out a final deal on Iran's nuclear program, a task complicated by U.S. Secretary of State John Kerry's biking accident in Geneva. The six world powers have overcome one big hurdle though, Reuters reports, agreeing on a mechanism to restore United Nations sanctions if Iran is found to be in violation of the terms of a final deal.

Russia and China have resisted an automatic "snapback" of sanctions that overrides their vetoes on the U.N. Security Council, while Western powers insist that those vetoes not stymie the big stick in the nuclear deal. Under the arrangement described to Reuters, any suspected Iranian breach of the agreement would be taken up by a resolution-dispute committee that probably includes the six powers and Iran. The details of how that would work are still unclear, Reuters said, but Western officials sound optimistic.

"We pretty much have a solid agreement between the six on the snapback mechanism, Russians and Chinese included," one Western official said. "But now the Iranians need to agree." Along with Iranian acceptance of the snapback provision, negotiators have to agree on a timeline for phasing out sanctions and IAEA access to Iranian scientists and nuclear facilities

By The Week