"...this individual--whom I was told is a CIA officer assigned to the NSC--mentioned Valerie Wilson's CIA connection to one or more White House colleagues..."
Corn's 'Nation' column sorta hinting at Joseph leaking seems to have slipped into the 'premium' access section, but consider the following:
snip
Meanwhile, a senior CIA official, Alan Foley, told the Senate Select Committee on Intelligence that he, too, was skeptical of the uranium claim, and said he had urged the NSC's chief weapons proliferation expert, Robert Joseph, to leave it out of the president's speech.
Wilson's wife works with Foley in the CIA's Nonproliferation Center.
On the other side of the dispute, the NSC's Joseph is said to be an ally of Cheney's chief of staff, I. Lewis "Scooter" Libby.
"Foley fought with Joseph about keeping the Niger claim out of the State of the Union," Cannistraro explained. "Cheney and Libby made sure it got in. Then you get a report from the CIA casting doubt on the authenticity" -- Ambassador Wilson's report.
"The leak was to punish Wilson, to disparage him with the suggestion of nepotism," he said. In other words, he suggested, the leaker was arguing that Wilson's report should not be taken seriously because he only got the job through his wife's intercession. (Wilson says his wife was not the person responsible for sending him to Africa.)
snip
http://www.sunspot.net/news/nationworld/bal-leak1001,0,653016.story?coll=bal-home-headlinesHowever, Corn makes the assumption that Joseph (NSC) needed Foley (CIA) to learn or confirm that Plame was CIA. Maybe so, but possibly Joseph could have 'come across' this on his own, since Joseph and Plame both worked proliferation at high levels in the executive branch.
However, I am convinced that Dr. Robert Joseph is the smoking pipe into the White House. Foley, though, is just one of a range of possible sources to Joseph.