I asked retired Lt. Gen. Michael Hayden, former director of the National Security Agency, whether it's unlawful or even unusual for someone in Rice's position to ask the NSA to unmask the names of Americans caught up in intercepts. He replied, in an email, "Absolutely lawful. Even somewhat routine."

He added, "The request to unmask would not be automatically granted. NSA would adjudicate that, although I'm certain a request from the national security adviser would carry great weight."

Hayden also said, "There are very plausible, legitimate reasons why she would request such information." Though he didn't elaborate on what those reasons might have been, the pertinent regulations specify that unmasking might be requested, and allowed, if the names in question are pertinent to foreign intelligence. When Rice made her request, there were ongoing investigations of Russia's involvement in the election, of the role Trump advisers might have played in this involvement, and of efforts by some of these advisers to undermine U.S. foreign policy, specifically on sanctions toward Russia.

"To summarize, on its face, not even close to a smoking gun."

It's worth noting that we don't know--or at least no news story about the incident has reported--whether the NSA granted Rice's request and gave her the unmasked names. Even if she did, Hayden emphasized in his email, "the identities would be unmasked only for her"--and not for any other official who received the transcript.

"To summarize," Hayden wrote in his email, "on its face, not even close to a smoking gun."

It's hardly out of the ordinary for a White House official like Rice, with high security clearances, to request unmasking. In Tuesday's Washington Post, Glenn Kessler quotes Michael Doran, a former NSC aide under President George W. Bush, as saying, "I did it a couple of times."