The Americans face their own constraints at home: A letter from key members of the Senate to President Obama describes what a deal to prevent Iran from producing a weapon should look like, and suggests that anything short of that would not lead to the lifting of sanctions, the only incentive the American team can dangle in front of the Iranians.
It was a reminder for Mr. Kerry that there is not one negotiation underway to strike this deal, but three. Mr. Kerry and his counterparts from five other nations are struggling to reach an accommodation with Mohammad Javad Zarif, Iran’s American-educated foreign minister, who has been camped out for the past 11 days in the Coburg Palace, which has become a luxury dormitory for the American, Western European, Russian and Chinese negotiators who are living and working just doors away from one another.