CIA documents already released have now been made accessible online via CREST (CIA Records Search Tool). I learned of this here and have just completed a fairly quick sift through the 247 documents produced by an Advanced Search using the term ‘diplomatic cover’ (inverted commas included, of course). The majority are ‘open source’ (press clippings, and so on) but there are also some interesting in-house papers (letters. memos, reports, etc), albeit inevitably redacted in places. As a result of what I have read, I am in the process of adding to the Updating Page for the chapter on Secret Intelligence in my textbook. I should add that I realised belatedly that a search using the term ‘official cover’ would be more productive, and indeed this turns up 659 documents, with a much greater preponderance of those generated by the CIA itself. (I have now, 6 Feb., sifted these as well.) A serious student of the interface between diplomacy and secret intelligence should certainly look at these as well. Have a look.