Secretary of State John Kerry and his Russian counterpart, Sergey V. Lavrov, announced that they had agreed on the delivery over the next few days of desperately needed aid to besieged Syrian cities, to be followed by a “cessation of hostilities” within a week on the way to a more formal cease-fire. “We have agreed to implement a nationwide cessation of hostilities in one week’s time,” Mr. Kerry said early Friday morning, after all-day meetings. “That is ambitious.” “The real test is whether all the parties honor those commitments,” he said, sitting next to Mr. Lavrov, the two men doing their best to appear cooperative after weeks of trading accusations over the accelerated Russian air campaign that has given new support to the government of Syria ’s president, Bashar al-Assad . If executed, the agreement, forged by the International Syria Support Group, would mark the first sustained […]