Diplomats missed another deadline for a nuclear deal with Iran and may prolong talks until the end of the week or beyond, as they spar over an arms embargo and what would happen if the accord is breached. World powers extended until July 10 the interim arrangement that freezes Iran’s most sensitive nuclear work in exchange for limited relief from sanctions. While the negotiators in Vienna are playing down talk of deadlines, the timetable for review by the U.S. Congress means that any further easing of the curbs will be delayed by at least a month if a final agreement isn’t reached by Friday morning. “We’re frankly more concerned about the quality of the deal than we are about the clock, though we also know that difficult decisions won’t get any easier with […]