Compromised

David Petraeus had to go as the head of the CIA. Trying to keep an affair secret left him open to blackmail from anybody with knowledge of the affair. And it set a bad example for those under him.

I don't suspect this has anything to do with the Benghazi hearings coming up. I'll guess--but don't know--that he'd have less leeway to avoid questions as a private citizen than as head of the CIA. Indeed, had Petraeus stayed, he'd have been vulnerable to pressure to follow their lead from anyone in the White House with knowledge of the affair.

If politics entered into the timing of this decision, it was probably election driven. Like the Iran drone incident was probably affected, this might have been delayed out of fear that in a close election they might have mattered to enough people to sway the election.

It is disappointing that a general who did so much to make the surge offensive in Iraq work ends his career under such a cloud of personal and professional failure.

UPDATE: Of course, the bizarre nature of his testimony to Congress on September 14th that the Benghazi attack was caused by anti-video sentiment has to raise questions about whether Petraeus was under pressure to blame the video to support the administration's then-current view that the video was responsible.

Now, of course, the president claims he always knew it was terrorism despite that Petraeus cover testimony. Curiouser and curiouser.