Finally America has its George Smiley, the fictional master spy from the John le Carré novels. Smiley knew the importance of a spy agency being willing to get to the bottom of its own major cock-ups.

Attorney General William Barr has been given power by Donald Trump to declassify classified material. He told CBS that stories offered by the FBI about its investigation of the Trump campaign don’t “hang together.” The same could be said for a more consequential enigma of the 2016 election, concerning the alleged Russian intelligence...