I am sad that Gen. David Petraeus resigned because he had an extramarital affair. What a shame to lose the services of such a brilliant person over such a personal episode.
If his family is aware of his peccadillo, he couldn't be blackmailed. So if he kept his position he would remain as qualified and effective as ever. Besides, if everyone inside the Beltway who has an affair resigns and leaves, Washington, D.C., will become a ghost town.
The general's behavior is not proper, but an affair is a silly reason to lose the services of a very talented citizen.