When President Obama began making the case for a deal with Iran that would delay its ability to assemble an atomic weapon, his first argument was that a nuclear-armed Iran would set off a “free-for-all” of proliferation in the Arab world. “It is almost certain that other players in the region would feel it necessary to get their own nuclear weapons ,” he said in 2012. Now, as he gathered Arab leaders over dinner at the White House on Wednesday and prepared to meet with them at Camp […]