Secretary of State John Kerry said on Sunday that the United States and Iran may fail to reach a final nuclear agreement despite the talks being extended past their June 30 deadline so that the sides could hash out remaining differences over the scope and scale of the Islamic Republic’s contested nuclear program. Western observers suggested the statement from Kerry was designed to provide cover for the administration if a deal with wide-ranging concessions to Iran is struck. Kerry told reporters in a brief press conference Sunday afternoon that he is prepared to leave town without a deal that has...