According to the CIA and the court that tried the Libby case (D.C. Dist, Walton, J.) Valerie Plame was a covert agent at the time her identity was leaked. She was what's called a NOC. "Non official cover" which means she was supposedly employed by a private company rather than supposedly employed by the State Department and stationed at an embassy (OC). According to the current director of the CIA, she had been overseas on behalf of the CIA, under cover, at least once during the past five years. Ironically, her field of expertise was "nuclear proliferation" and her area of interest was Iran. It might have been better for all of us, if she could have stayed at her job.
It appears that both Richard Armitage (who leaked to Woodward and later Novak), and Karl Rove who confirmed the Armitage leak for Novak were both fed Plame's identity by Libby -- probably at Cheney's direction. Indeed, Libby's lies in this regard represent one of the perjury charges. Rove did not get indicted because he changed his story about hearing about Plame from a reporter to hearing about Plame directly from Libby. For that matter, Ari Fleisher and Dan Bartlett also heard about Plame from Libby. Armitage supposedly learned about Plame from a State Department Memo on Wilson prepared at Cheney/Libby's request.
Libby was not convicted of "forgetting" or getting confused about what he said to a reporter, or what a reporter said to him. Libby was convicted of outright fabrication to an investigation (not a big deal in my book) and to a Grand Jury (big deal) and of Obstruction of Justice (very big deal). According to Fitzgerald, the U.S. Attorney who took the case when Attorney General Ashcroft realized he was hopelessly conflicted. It was Libby's obstruction of justice that kicked sand in Fitzgerald's face making it impossible for him to complete the investigation, and left "a cloud over the Vice President," who had left a trail of evidence strong enough for suspicion, but insufficient for indictment at least by a U.S. Attorney as cautious as Fitzgerald.
It should be pointed out that Fitzgerald is a Bush appointee, a registered Independent and enough of a "loyal Bushie" that he survived the now infamous US Attorney replacements. When Ashcroft recused, Fitzgerald was appointed by the then Deputy Attorney General, James Comey.
Finally, do not confuse the failure to bring charges on the underlying crime with that being indicative that no underlying crime was not committed. On the contrary, it is indicative that the obstruction of justice was mostly successful.
You're entitled to your opinion, but not your own facts.