From Secrecy News… Great title for a secret report: Maybe You Had to Be There: The SIGINT on Thirteen Soviet Shootdowns of U.S. Reconnaissance Aircraft.
Who knew cryptologists had such a sense of humor?

NSA Declassifies Secret Document After Publishing It

May 14th, 2012 by Steven Aftergood
The National Security Agency last week invoked a rarely-used authority in order to declassify a classified document that was mistakenly posted on the NSA website with all of its classified passages intact.

The article is a historical study entitled Maybe You Had to Be There: The SIGINT on Thirteen Soviet Shootdowns of U.S. Reconnaissance Aircraft. It was written by Michael L. Peterson and was originally published in the classified journal Cryptologic Quarterly in 1993.

Late in the afternoon of May 11 (not May 9 as stated on the NSA website), the NSA published a formally declassified version of the article with the annotation “Declassified and approved for release by NSA… pursuant to E.O. 13526 section 3.1(d)….”

Read on at Secrecy News (another playful title!) including this nugget of real politik/how bureaucrats work:

But [giving the NSA a four day extension to answer questions about the document] proved to be a futile gesture on our part, since the NSA Public Affairs Office in the end refused to answer any of the questions we posed. In retrospect, it appears that NSA never intended to answer any of our questions but simply wanted to preempt the reposting of the classified document by hastily declassifying it.

– P

Thanks to @trevortimm