WASHINGTON (AP) -- The resignation of CIA Director David Petraeus has brought a sudden and unexpected end to the public career of a four-star general who led U.S. troops in Afghanistan and Iraq and was thought to be a potential candidate for president.
Petraeus admitted to an extramarital affair in tendering his resignation, which President Barack Obama accepted Friday.
Several U.S. officials with knowledge of the situation say Petraeus carried on the affair with his biographer Paula Broadwell, a reserve Army officer. Two of the officials say the FBI discovered the relationship by monitoring Petraeus' emails, after being alerted Broadwell may have had access to his personal email account.
For the director of the CIA, engaging in an extramarital affair is considered a serious breach of security and a counterintelligence threat. If a foreign government had learned of the affair, the reasoning goes, Petraeus or Broadwell could have been blackmailed or otherwise compromised.
Failure to resign also could create theperception for the rank and file that such behavior is acceptable.
Broadwell wrote "All In: The Education of General David Petraeus" with Vernon Loeb. The book was published in January. Broadwell has not responded to messages seeking comment.