I would say 'unbelievable', but unfortunately it is not really that hard to believe.
"The resignation of David H. Petraeus as CIA director followed an FBI investigation of many months, raising the question of why he was not forced out until after the election.
The investigation began last spring, but the FBI then pored over his emails when he was stationed in Afghanistan.
Given his top secret clearance and the fact that Petraeus is married, the FBI continued to investigate and intercept Petraeus’ email exchanges with the woman. The emails include sexually explicit references to such items as sex under a desk.
Such a relationship is a breach of top secret security requirements and could have compromised Petraeus.
At some point after Petraeus was sworn in as CIA director on Sept. 6, 2011, the woman broke up with him. However, Petraeus continued to pursue her, sending her thousands of emails over the last several months, raising even more questions about his judgment.
FBI agents on the case expected that Petraeus would be asked to resign immediately rather than risk the possibility that he could be blackmailed to give intelligence secrets to foreign intelligence agencies or criminals. In addition, his pursuit of the woman could have distracted him as the CIA was giving Congress reports on the attack on the Benghazi consulate on Sept. 11.
Still, the White House, with concurrence by the FBI and Justice Department, held off on asking for Petraeus’ resignation until after the election. His resignation occurred three days after the election, avoiding the possibility that Obama’s ill-fated appointment of Petraeus could become an issue in the election.
FBI agents on the case were aware that such a decision had been made to hold off on forcing him out until after the election and were outraged.
“The decision was made to delay the resignation apparently to avoid potential embarrassment to the president before the election,” an FBI source says. “To leave him in such a sensitive position where he was vulnerable to potential blackmail for months compromised our security and is inexcusable.”"