A month before the 2016 presidential election, the FBI met Christopher Steele in Rome and apparently unlawfully shared with the foreign opposition researcher some of the bureau’s most closely held secrets, according to unpublicized disclosures in the recent Justice Department Inspector General report on abuses of federal surveillance powers. What’s more, Steele, the former British spy who compiled the “dossier” of conspiracy theories for the Hillary Clinton campaign, was promised $15,000 to attend the briefing by FBI agents eager to maintain his cooperation in their Trump-Russia collusion investigation codenamed Crossfire Hurricane. That investigation was so closely guarded that only a...