When a prosecutor doesn’t indict, that might mean no crime was committed.
But it also might mean:
A. That a crime was committed, but there isn’t enough admissible evidence to prove it beyond reasonable doubt.
B. That a provable crime was committed, but by somone who is immune from prosecution by reason of office (the President probably can’t be indicted in federal court) or because of immunity given in return for testimony.
C. That a provable crime was committed by someone who can be indicted, but that it would be unjust or imprudent to bring a prosecution.
Based on Fitzgerald’s “umpire” analogy at his post-indictment press conference, my betting is on (A). Cheney is probably guilty of heading a conspiracy to violate the Espionage Act, but most of the evidence to prove it would be Libby’s testimony, and Libby’s multiple lies to the grand jury made it impossible to convict anyone based on Libby’s word.
If this is right, don’t expect to hear it from Fitzgerald. Prosecutors indict; they don’t tattle.