One of the latest Hillary Clinton emails to be revealed by the State Department included discussion of an Afghan national on the CIA’s payroll – an exchange “presumed to cause damage to the national security” under President Obama’s executive orders.

Fox News reports this particular email exchange referred to a story in the New York Times, but it was also one of the emails deemed sensitive enough to require a special clearance to review, even today.

Based on the timing and other details, the email chain likely refers to either an October 2009 Times story that identified Afghan national Ahmed Wali Karzai, the half-brother of then-Afghan president Hamid Karzai, as a person who received “regular payments from the Central Intelligence Agency” — or an August 2010 Times story that identified Karzai aide Mohammed Zia Salehi as being on the CIA payroll. Ahmed Wali Karzai was murdered during a 2011 shoot-out, a killing later claimed by the Taliban.

Fox News was told the email chain included then-Secretary of State Clinton and then-special envoy to Afghanistan and Pakistan Richard Holbrooke and possibly others. The basic details of this email exchange were backed up to Fox News by a separate U.S. government source who was not authorized to speak on the record.

It’s unclear who initiated the discussion – Clinton, Holbrooke or a subordinate – or whether the CIA’s relationship with the Afghan national was confirmed, because the classified documents are not public.

The CIA refused to comment on the Fox News story, as did Clinton attorney David Kendall. Richard Holbrooke died in 2010.

Fox suggests this email might be one of the documents Rep. Chris Stewart of the House Intelligence Committee was thinking about when he said on February 3, “I have never read anything more sensitive than what these emails contain. They do reveal classified methods. They do reveal classified sources and they do reveal human assets.”

While Clinton and her partisans will try to portray this email as an example of over-classification, Fox News was ready with a pre-buttal to that argument:

National security and intelligence experts emphasized to Fox News that security clearance holders are trained to not confirm or deny details of a classified program in an unclassified setting, which would include a personal unsecured email network, even if the classified program appears in press reports.

“The rules of handling classified information dictate if something is reported in open source [news reports] you don’t confirm it because it’s still classified information,” said Dan Maguire, who spent more than four decades handling highly classified programs and specialized in human intelligence operations.

As secretary of state, Clinton signed at least two non-disclosure agreements (NDA) on Jan. 22, 2009, and received a briefing from a security officer whose identity was redacted. As part of the NDA for “sensitive compartmented information” (SCI), Clinton acknowledged any “breach” could result in “termination of my access to SCI and removal from a position of special confidence and trust requiring such access as well as the termination of my employment or any other relationships with any Department or Agency that provides me with access to SCI.”

It will also be interesting to watch liberals who wailed for years, all the way to Hollywood, about the “exposure” of desk jockey Valerie Plame blow off the cavalier treatment of human assets in the perpetual war zone of Afghanistan… especially if it was Hamid Karzai’s half-brother, and he ended up dead.

Clinton’s defense boils down to an argument that the rules simply don’t apply to her.

She knew exactly how this sensitive information was supposed to be handled – or, at least, she signed sworn documents attesting that she understood. She decided to waive the rules based on her own highly questionable judgment, because she really wanted that private, FOIA-proof, subpoena-insulated email server.

It bears repeating that the intelligence apparatus of the United States will not survive a total breakdown in protocol, with every official deciding they have the unilateral authority to waive the rules at their own convenience. Protecting this nation’s vital intelligence requires obedience to the rules beforehand, not lengthy arguments after the fact about how much damage was done by ignoring the rules, or whether the rule-breaker should be politically untouchable.