Reuters has a rundown of the timeline for the Petraeus investigation:
2011-2012: Broadwell and Petraeus extramarital affair started after he left military service and ended about four months ago.
Sometime within the past four or five months – one official said “early summer” – a woman complained to the FBI about harassing emails that were later determined to have been written by Broadwell. In the course of investigating that complaint, the FBI discovered an affair between Broadwell and Petraeus.
Week of October 21: Federal investigators interview Broadwell.
Week of October 28: Federal investigators interview Petraeus. Prosecutors conclude afterward they likely will not bring criminal charges.
Tuesday, November 6, Election Day, at about 5 p.m.: the FBI notifies Director of National Intelligence James Clapper, who oversees the CIA and other intelligence agencies, about Petraeus. Clapper speaks to Petraeus that evening and again Wednesday and advises him to step down.
Wednesday, November 7: Clapper informs White House National Security Council official that Petraeus may resign and President Barack Obama should be informed. The president is told about it later that day.
Thursday, November 8: At 11 a.m. a Petraeus meeting with foreign dignitaries scheduled for 2:30 p.m. is canceled and his visitors are informed he has to go to the White House to meet with Obama. Petraeus meets with Obama at the White House and offers his resignation, explaining the circumstances behind it. Obama did not immediately accept the resignation.
Friday, November 9 – Obama calls Petraeus and accepts his resignation.
There have been some questions raised about the timing of Petraeus’s resignation, but this timeline seems reasonable. The FBI and Attorney General Eric Holder knew about the affair as early as late summer, according to the Wall Street Journal, but there’s no indication they believed there was a security breach at that point. They may not have informed other intelligence officials or the president about it over the summer because they thought they had discovered an affair, and nothing more.
There is also no evidence Petraeus was pushed out because of his role in the Benghazi response. The fact that he resigned right after the election and right before another closed-door Benghazi hearing is interesting, to say the least, but it could be just that — a coincidence. There is no need for conspiracy theories in this case.
That still doesn’t mean journalists shouldn’t question the administration’s account, particularly why Congress and the director of national intelligence weren’t informed of the investigation by the FBI when classified information was discovered on Paula Broadwell’s computer. There are also questions about the FBI whistle-blower who tipped off House Majority Leader Eric Cantor in October — what was this person’s motivation, and what was he concerned about? But from what we know so far, it doesn’t sound like there is anything sinister going on here.