WASHINGTON

As Lyndon Johnson said, the two things that make leaders stupid are envy and sex.

Macbeth kills a king out of envy. Egged on by an envious Iago, Othello smothers his wife out of a crazed fear of her having sex with his lieutenant.

Now another charismatic general has shattered his life and career over sex. When you’ve got a name like a Greek hero, and a nickname like a luscious fruit, isn’t hubris ripe to follow?

It’s been a steep fall for Peaches Petraeus, once the darling of Congress and journalists, Republicans and Democrats, Paula Broadwell and Jill Kelley.

Washington is suffused with schadenfreude. Yet President Obama and others felt genuinely sad to see a man so controlling about integrity and image — he warned protégés that “someone is always watching” — spin out of control on integrity and image. As Shakespeare wrote in “Othello”: “Reputation, reputation, reputation.”

As a West Point cadet, David Petraeus clambered up the social ladder by winning the superintendent’s daughter; now he has been brought down by his camp followers clambering up the social ladder.

Even when he was the C.I.A. director, Petraeus’s ego was so wrapped up in being a shiny military idol that, according to The Washington Post, he recently surprised guests at a D.C. dinner when he arrived to speak wearing his medals on the lapel of his suit jacket.

His fall started as Sophocles and turned sophomoric, a mind-boggling mélange of “From Here to Eternity,” “You’ve Got Mail,” “The Real Housewives of Centcom,” and “Keeping Up With the Kardashians.” It features toned arms, slinky outfits, a cat fight, titillating e-mails, a military more consumed with sex than violence, a plot with more inconceivable twists than “Homeland,” and a Twitter’s-delight lexicon: an “embedded” mistress named Broadwell, a biography called “All In,” an other-other woman of Middle East ancestry who was a “social liaison” to the military, a shirtless F.B.I. agent crushing on the losing-her-shirt-to-debt Tampa socialite, a pair of generals helping the socialite’s twin sister with a custody case, and lawyers and crisis-management experts linked to Monica Lewinsky, John Edwards and the ABC show “Scandal.”

“This is The National Enquirer, ” an alarmed Senator Dianne Feinstein told Wolf Blitzer of CNN. If only it were that highbrow. Now that erotic activity is entwined with the Internet, rather than closeted in hideaway Capitol offices and Oval Office pantries, it’s even more likely to be a trip wire for history.

It is disturbing that an ethically sketchy, politically motivated F.B.I. agent could spark an incendiary federal investigation tunneling into private lives to help a woman he liked and later blow it up to hurt a president he didn’t like.

It’s also worrisome that the nation’s spymaster — who had presided in a military where adultery could result in court-martial — could not have found a more clandestine manner of talking naughty to his biographer babe than a Gmail drop box, a semiprivate file-sharing system used by terrorists, teenagers and authors.

It’s understandable that men accustomed to being away from their families and cloistered with other men in Muslim countries where drinking and blowing off steam are frowned upon might get used to cavorting on e-mail.

But Petraeus should have realized that the Chinese and Russians were snooping and sent Paula Broadwell an Enigma e-mail: “I would like your insights into the debate over COIN versus CT in Helmand Province. Our HVT kills are falling a little short of the mark. Let’s discuss.”

And Broadwell could have sent ones more like: “I’ve been reading Chapter 3 notes and the Galula theory of counterinsurgency confuses me. Hope you can clarify.”

The scandal is a good reminder that, although John McCain and Sarah Palin urge total trust and blank checks for the generals, these guys are human beings working under extremely stressful circumstances, and their judgments are not beyond reproach.

Petraeus’s Icarus flight began when he set himself above President Obama.

Accustomed to being a demigod, expert at polishing his own celebrity and swaying public opinion, Petraeus did not accept the new president’s desire to head for the nearest exit ramp on Afghanistan in 2009. The general began lobbying for a surge in private sessions with reporters and undercutting the president, who was trying to make a searingly hard call.

Petraeus rolled the younger commander in chief into going ahead with a bound-to-fail surge in Afghanistan, just as, half a century earlier, the C.I.A. had rolled Jack Kennedy into going ahead with the bound-to-fail Bay of Pigs scheme. Both missions defied logic, but the untested presidents put aside their own doubts and instincts, caving to experience.

Once in Afghanistan, Petraeus welcomed prominent conservative hawks from Washington think tanks. As Greg Jaffe wrote in The Washington Post, they were “given permanent office space at his headquarters and access to military aircraft to tour the battlefield. They provided advice to field commanders that sometimes conflicted with orders the commanders were getting from their immediate bosses.”

So many more American kids and Afghanistan civilians were killed and maimed in a war that went on too long. That’s the real scandal.