The chair of the Joint Chiefs of Staff Admiral Mike Mullen declared Sunday that the US now believes Iran has amassed enough uranium that, with further purification, could be used to build an atomic bomb. Mullen’s statement on CNN went further than previous official judgments of the Iranian nuclear threat. But in a separate interview, Defense Secretary Robert Gates downplayed the immediate threat posed by Iran. During an interview on Meet the Press, Gates said, “They are not close to a stockpile; they are not close to a weapon at this point. So there is some time.”