Petraeus fell because of the affair, the drone program, or Benghazi — which is it?

"Central Intelligence Agency Director David Petraeus resigned after a probe into whether someone else was using his email led to the discovery that he was having an extramarital affair," The Wall Street Journal reports, without naming sources. I selected some items from the article that relate to the time line:

It was the second national-security revelation to come to light in the two days after President Barack Obama won re-election. On Wednesday, the Pentagon acknowledged that Iranian fighter planes had fired on an unmanned reconnaissance drone five days before the election....

Mr. Petraeus was scheduled to testify before the Senate intelligence committee next week. Michael Morell, who was named acting director of the CIA after Mr. Petraeus's resignation, will appear instead....

Administration officials said the White House was briefed on the affair Wednesday by Director of National Intelligence James Clapper. Mr. Obama was informed Thursday by his staff and met with Mr. Petraeus that day. Mr. Petraeus then offered to resign. The announcement came Friday afternoon....

The computer investigation began late this spring, according to a person familiar with the investigation. Mr. Petraeus wasn't interviewed by the FBI until recently....

He presided over a moderation of the CIA's controversial drone program to take into greater account diplomatic sensitivities, a shift that sometimes put him at odds with the head of the agency's Counterterrorism Center.

Let's reorganize those facts:

1. Drones. Petraeus had moderated the drone program to make it more diplomacy-sensitive,  the head of the CIA Counterterrorism Center was not happy with that, and Iran fired on a drone 5 days before the election.

2. Benghazi. Petraeus was about to represent the CIA in testimony before Congress and now he will not.

3. The gmail account. This problem dates back to last spring, but Petraeus was only interviewed about it recently, the White House was briefed on Wednesday and Petraeus was confronted and pushed/fell into resignation in the next 2 days.

Given the timing of these 3 sets of facts, it's hard to believe Petraeus left because of the affair or the problem with his gmail. It seems much more likely to have to do with the drones or Benghazi.

By the way, who is the head of the CIA Counterterrorism Center?

Roger, which is the first name of his cover identity, may be the most consequential but least visible national security official in Washington — the principal architect of the CIA’s drone campaign and the leader of the hunt for Osama bin Laden. In many ways, he has also been the driving force of the Obama administration’s embrace of targeted killing as a centerpiece of its counterterrorism efforts.

Colleagues describe Roger as a collection of contradictions. A chain-smoker who spends countless hours on a treadmill. Notoriously surly yet able to win over enough support from subordinates and bosses to hold on to his job. He presides over a campaign that has killed thousands of Islamist militants and angered millions of Muslims, but he is himself a convert to Islam.

His defenders don’t even try to make him sound likable. Instead, they emphasize his operational talents, encyclopedic understanding of the enemy and tireless work ethic.

“Irascible is the nicest way I would describe him,” said a former high-ranking CIA official who supervised the counterterrorism chief. “But his range of experience and relationships have made him about as close to indispensable as you could think.”

Critics are less equivocal. “He’s sandpaper” and “not at all a team player,” said a former senior U.S. military official who worked closely with the CIA. Like others, the official spoke on the condition of anonymity because the director of CTC — as the center is known — remains undercover.