CIA Director David Petraeus has resigned, citing "extremely poor judgment" for having an extramarital affair.

"Yesterday afternoon, I went to the White House and asked the President to be allowed, for personal reasons, to resign from my position," Petraeus said in a letter to CIA colleagues. "After being married for over 37 years, I showed extremely poor judgment by engaging in an extramarital affair. Such behavior is unacceptable, both as a husband and as the leader of an organization such as ours."

"This afternoon, the President graciously accepted my resignation."

President Obama said in a statement that Petraeus "has provided extraordinary service to the United States for decades."

"By any measure, he was one of the outstanding General officers of his generation, helping our military adapt to new challenges, and leading our men and women in uniform through a remarkable period of service in Iraq and Afghanistan, where he helped our nation put those wars on a path to a responsible end," Obama said. "As Director of the Central Intelligence Agency, he has continued to serve with characteristic intellectual rigor, dedication, and patriotism. By any measure, through his lifetime of service David Petraeus has made our country safer and stronger."

The resignation comes as hearings on the Benghazi consulate attack and its aftermath are slated for early next week. Will he still testify as to his role in providing intelligence and possibly advice to the Obama administration? As readers know well, the Obama administration has changed its story on what happened, and cited intelligence reports as the basis for its false reports that the attack was the result of a riot over the YouTube Mohammed video. Petraeus would be in a position to provide considerable insight as to what was provided to the White House.

I cannot see a reason why his resignation would affect his ability to testify, though he might potentially be denied access to classified documents in preparation for his testimony.

The timing of the resignation is startling, to say the least. It could be a coincidence, of course.

There is no question that an affair presented a potential source of blackmail, and that his effectiveness as CIA Director could be compromised. So, he did the right thing in leaving office. But was he being blackmailed, and if so, by whom? We probably will never know.

The Benghazi Affair has become an even bigger embarrassment to the United States and to the Obama Administration.

Update: Fox News reports that Petraeus will not testify before the House committee next week. This raises a very unpleasant smell. Why can't the committee subpoena him? He was a witness to what happened.