John Sipher spent twenty-eight years as a clandestine officer in the C.I.A., and ran the agency’s Russia program before retiring, in 2014. He said of Steele’s memos, “This is source material, not expert opinion.” Sipher has described the dossier as “generally credible,” although not correct in every detail. He said, “People have misunderstood that it’s a collection of dots, not a connecting of the dots. But it provided the first narrative saying what Russia might be up to.” Alexander Vershbow, a U.S. Ambassador to Russia under George W. Bush, told me, “In intelligence, you evaluate your sources as best you can, but it’s not like journalism, where you try to get more than one source to confirm something. In the intelligence business, you don’t pretend you’re a hundred per cent accurate. If you’re seventy or eighty per cent accurate, that makes you one of the best.”