Gen. David Petraeus has resigned as director of the Central Intelligence Agency because of a little action on the side? Unless he was sleeping with a double-agent Mata Hari who was working for Al Qeada, the question is obviously “why?” What is this Nathaniel Hawthorne Sunday-school obsession that Americans have about puritanically condemning the painful but not uncommon way of things when a marriage has lasted two or three decades?

Gen. David Patreaus and wife Holly sometime within the last two or three years.

David and Holly Patreaus when he graduated from West Point in the mid ’70s.

What does a perfectly normal and, I would add, perfectly understandable infidelity (powerful men of a certain age often succumb to temptation, particularly when their wives haven’t aged in a flattering way)…what does this have to do with being able to do your job in an effective manner?

Slate‘s Fred Kapalan is reporting that the woman Patreaus was having it off with is the attractive author of a Petreaus biography (“All In: The Education of General David Patreaus“) named Paula Broadwell.

I’m not trying to be cruel, but please…compare the above photographs and come down off your moralistic horse and be honest. Cut the crap. The Patreaus’s have been married for 37 years. It’s perfectly normal for powerful husbands in their 40s, 50s or 60s to think about the unthinkable when sufficiently motivated.

You know what I mean. The French don’t look at affairs this way. Nor the Italians. I’m not saying something like this isn’t difficult or that it isn’t humiliating for poor Holly Patreaus — obviously it’s a rough episode all around. But again…who out there is genuinely surprised? Be honest.

MSNBC’s Andrea Mitchell announced the Pateaus resignation an hour ago, reading Petraeus’ farewell letter on air. Petraeus wrote that he had gone to the White House on Thursday and asked the president “for personal reasons” to resign. “After being married for more than 37 years I showed extremely poor judgment by engaging in an extramarital affair,” he wrote. “Such behavior is unacceptable, both as a husband and as a leader of an organization such as ours.”

Men all across the world are sympathizing as we speak.

Paula Broadwell’s reported involvement with Petreaus triggered his resignation.

“It had long been rumored that something was going on between Petraeus and Broadwell,” Kaplan writes. “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.”

Powerful people have affairs, and they’ve been happening since Ceasar and Cleopatra. Leave them alone. Sexual connections between consenting adults, within or without the sanctity of marriage, are nobody’s damn business except those immediately involved.