Can mediators save the Iran deal despite the Lebanon poison pill?

On June 18, Iran and the U.S. signed an agreement, titled the “Islamabad Memorandum,” which committed both countries to an immediate and permanent end to hostilities, the reopening of the Strait of Hormuz, and 60 days of negotiations to reach a final agreement.Within 48 hours, Iran had closed the strait again. The reason was neither the failure of nuclear negotiations (which hadn’t yet commenced) nor a dispute over sanctions relief. It was Lebanon, a country that appears in the deal’s opening clause three times. The Lebanese government was not a party to the negotiations, nor was it consulted.