The Valerie Plame affair can be summed up: her husband (Joe Wilson) drew attention with some discredited articles, Novak found out about her in a book called "Who's Who in America", since she wasn't an active agent: no crime was committed, and why no one was prosecuted. Joe's claims showed that Saddam TRIED to secure yellowcake for his WMD program, which proved the opposite of what he thought. And Joe, Valerie and the media perpetuated the lie that they were somehow wronged, and the rubes buy in.
Saddam and WMD's
- Read more at: Bush_lied...
In late 2002, the Bush administration was soliciting support for a policy of military force to Saddam to comply with U.N. regulations once and for all, or else.
And in his January 2003 State of the Union address, President George W. Bush did a 5,400 word speech, laying out an ultimatum to Saddam and a justification for war. It included dozens of reasons for the war, from WMD's, to failing to comply with various U.N. resolutions, and so on -- but it also contained the following 16 words (vetted by the CIA), "The British Government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa". The anti-Bush-Administration fanatics locked on to those 16 words, and ignored the rest. And in a logic defying move, seemed to figure that if they could prove that the Brits or Americans were wrong on Saddam trying to get yellowcake, that it meant Bush was wrong for listening to the CIA and world's intelligence on everything else. It doesn't, but that's part of why Joe Wilson and Valerie Plame is such a big deal.
Niger and Yellowcake
Bush had understated things as it wasn't just the British that thought Saddam was going after Uranium. The British, American, French, Italian, and other intelligence agencies all had some evidence (mostly circumstantial and hearsay) that Iraq / Saddam had been negotiating to buy yellowcake (unprocessed Uranium-ore) from Niger. They all agreed that Saddam was seeking WMD's, and the Uranium, but for different reasons and sources.
The Italians had these documents that "proved it", those later turned out to be forged, and people made a stink, "see, it was all based on a forgery". However, while the French and Italians believed those docs, the Brits and Americans were concerned did not considered trustworthy (as of early 2002), so they were not in the assessments behind the 2003 State of the Union address, and this had nothing to do with U.S. or Brits (but they get brought up by folks trying to obfuscate the issue).
One of those smear merchants was Joseph C. Wilson (Valarie Plame's wife), who had gone on a "fact finding mission to Africa" and series of critical op-eds starting in The New York Times in March 2003  which he explained the nature of these documents and the government's prior knowledge of their unreliability for use in a case for war, then implied this was why we'd gone to war. Everything about that was wrong: the U.S. had not based the war on the falsified Italian documents, they'd based in on our own intelligence as well as the Brits.
On top of that Wilson's mission had lead the CIA to believe more than ever that Saddam had gone after Uranium. While Joe Wilson thought an Iraqi contingent going to Niger but being unable to acquire a secret deal for Uranium, proved the Bush position wrong -- for the CIA it did the opposite. As one British foreign official explained it to the Independent: “Niger has two main exports—uranium and chickens. The Iraqi delegation did not go to Niger for chickens.” So the CIA didn't care if one diplomat (Joe Wilson) didn't think they could get the uranium out, they saw confirmation that they were still trying to get more.
People forget that this whole mess was because Wilson's statements drew attention to him and his wife, and that he was wrong the whole time. And that Joe Wilson (or Valerie's) claim that the Bush administration outted his wife as retaliation for his dissent, have both been proven completely false. 
Since Wilson's erroneous article was part of a larger smear campaign by the media against Bush/Blair, it put pressure on the Administrations to release (declassify) more evidence/documents to support their points. But it was a losing battle, anything they didn't declassify was part of a conspiracy, and since all intelligence assessments have evidence for and against, the media could report the against (ignore the for case, or the conclusions) and mislead their readership. The left also attacked Bush at the time for declassifying things and being too open. (Seriously).
Shortly after Wilson's op-ed, Robert Novak revealed the identity of Wilson's wife (CIA analyst Valerie Plame) in an article "Mission to Niger".  The "Plame affair" or "CIA leak scandal" ensued as a result of the "unauthorized disclosure" of her identity.  This became another spun scandal by the anti-Bush left; "The Administration leaked her name as retaliation against Joe Wilson for his honest Whistle-Blowing". Only all this is demonstrably false.
It wasn't a scandal and no crime was actually committed by outting her. 
- Valerie Plame's identity as a CIA Officer was not a secret.
- She was an officer and not an active field agent.
- Since she was not active, and no one knew, the law against naming field agents didn't apply.
- And Novak had found out about Valarie through the book "Who's who in America"
- Novak had gotten details of her role from the CIA and others, and was asked not to mention her name.
- Novak had gotten confirmation of her from Scooter Libby by asking something along the lines of, "I heard Wilson's wife is in the CIA, and that's how he got to go to Niger in the first place", and Libby said "oh, you know about that". and "that's what he'd heard too". Since neither knew she had once been agent, this was not a crime. Scooter hadn't leaked the info, he accidentally confirmed it. But for it to have been a crime, she would have had to have been an active agent, on an assignment, which she was not.
- The only reason she was outted at all, was because her nitwit Husband drew attention to her, by going to Niger, writing an erroneous report, and drawing that attention.
Novak detailed all this at the time, as NOT being a scandal, and his sources and what happened -- but the myth of some big scandal continued to grow, along with independent investigation by the Democrats to find the source of this non-existent leak, over a non-existent crime. 
What often gets lost is how discredited and incompetent Joe Wilson and Valerie Plame was. If you're a covert agent, you probably shouldn't use your pull to get your husband onto a public investigation, and have him co-write stories for the New York Times (and books) which bash the current administration, at least not if you care about anonymity. Worse than that, Plame has gone on to write a book and sensationalize the lie that this was a conspiracy to get her, and the anti-Bush crowd gobbles that crap down without knowing better or reading up on what happened: they're called rubes. And if course when the Obama administration did what the Bush administration was accused of (but never did), the Press generally glossed over it. 
Not to mention that the Press fails to bring home the messages that:
- (a) Wilson's claims were all proven wrong
- (b) the faux scandal was not a scandal at all (no crimes committed)
- (c) the media memes that consist today, that Bush administration committed crimes by leaking her name for retaliation against Joe's whistle-blowing have all been proven false.
And any news agency that implies that last one, (and there are many), are Fake News sites.  The bigger scandal wasn't what the administration did, but what the anti-Bush people and the media did, and the mental gymnastics they went through to misinform the public.
Once the backlash hit, she tried to claim it was just a mistake because she was multitasking and texting at the same time. Plame watchers pointed out, that she must be busy a lot, as she'd tweeted similar anti-Semitic articles/views for years.
- Wilson's Editorials:
- Wilson and Yellowcake:
- Wilson/Plame are liars:
- Butler Report: http://en.wikipedia.org/wiki/Butler_Report
- Mission to Niger: http://www.washingtonpost.com/wp-dyn/content/article/2005/10/20/AR2005102000874.html
- Plame Affair:
- No Crime: http://humanevents.com/2007/03/19/im-not-a-lawyer-and-other-distortions-from-valerie-plame/
- Who's who:
- Novak on Novak:
- Obama did what Bush was accused of (to no media fanfare):
- Fake News examples (misleading summaries of what happened):
- Media Matters is a liar on what happened: http://mediamattersaction.org/message/onepagers/201305140001
- WaPo itself perpetuates the lie they debunked: