Published by BuzzFeed here, if this is fake news it was drafted by a master forger. On balance, I am inclined to think it authentic. It is said by doubters to have a few mistakes, but what documents don’t have them? Also, I disagree with the common press view that it should not have been published because it is ‘unverified and unverifiable’. On this argument, secret intelligence reports that turn up would never be seen by the public. Such documents obviously cannot cite their human sources for fear of jeopardizing careers and even lives. But those that come to light can be tested for veracity in some degree on the basis of their provenance* and internal evidence. On both of these counts, the Trump dossier cannot be dismissed lightly. The pity is that US-Russia relations should be improved and this will not help that cause.
*The author is the former SIS officer, Christopher David Steele, who had cover as Second Secretary (Chancery) in the British Embassy in Moscow from 1990 until 1993 and later as First Secretary (Financial) at the Paris embassy from 1998 until 2003, according to The Diplomatic Service List 2006. According to The New York Times, he then became SIS’s ‘top expert on Russia’ at its London headquarters at Vauxhall Cross, until retiring (early) in 2009 to become what an earlier era called an ‘intelligencer’, an intelligence-gatherer for hire, and one with a good reputation among his peers. In the latest edition of my textbook (see above), I have a new chapter, ‘Secret Intelligence’, that gives particular attention to the question of diplomatic cover for intelligence officers.
See also ‘UK’s former Moscow ambassador in spotlight over Trump dossier: Sir Andrew Wood says he rates judgment of report author Christopher Steele, who “would not make things up”’, Guardian, 13 January 2017
UPDATE: PARTIAL CORROBORATION REVEALED HERE BY CNN ON 10 February