Petraeus resigned as CIA director on Friday, citing the affair. In a letter to his staff, Petraeus wrote:
"Yesterday afternoon, I went to the White House and asked the President to be allowed, for personal reasons, to resign from my position as D/CIA. 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."
Sources tell me that President Obama, who has been getting along with Petraeus very well in the past couple years, agonized for 24 hours over the letter of resignation before accepting it. The move no doubt ends the career of the most famous, and perhaps most strategically astute, American military commander in decades.
Petraeus has attracted detractors—fellow officers and some senior White House aides—who regarded him as a “showboat” and excessively ambitious.
It had long been rumored that something was going on between Petraeus and Broadwell. Her book, co-written with Vernon Loeb, is widely regarded as a valentine to the general. When she was embedded with him in Afghanistan, they went on frequent 5-mile runs together. But Petraeus went on 5-mile runs with many reporters, and few people who knew him took the rumors seriously. In his personal life, he’s always been seen as a straight shooter, a square. Few could have imagined that his end would come as the result of a morals scandal.
[Elsewhere on The Slatest, watch video of Broadwell singing Petraeus' praises during a string of media appearances during her book tour earlier this year. Also, read about how the affair was uncovered and who might replace Petraeus at the CIA.]
Fred Kaplan is Slate's "War Stories" columnist and author of the forthcoming book, The Insurgents: David Petraeus and the Plot to Change the American Way of War. He can be reached at firstname.lastname@example.org.