Anyone who accepts appointment as CIA Director undertakes an obligation to avoid clandestine irregularities in his or her personal life that could have an adverse impact on national security. Gen. Petraeus violated that obligation. He had to leave office.The fact that no damage to national security has (so far) been discovered is irrelevant. The way this matter has unraveled demonstrates why private conduct can have unforeseen consequences and create national security risks. This is not a question of the private morality of adultery--that's between him and his wife or his conscience--but rather a question of the public interest. It's interesting how so many journalists and other authorities have risen to Petraeus' defense. In the Washington Post, Ruth Marcus, Richard Cohen, David Ignatius and John Prados have penned columns condoning Gen. Petraeus and arguing that his personal pecadillo should not be grounds for his dismissal. The thrust of their columns is that our Nation has been disadvantaged by the loss of such a talented and competent public servant. To my mind, none of the columns has adequately addressed the potential risks to national security Gen. Petraeus' conduct posed, even in the absence of actual damage.I suspect there are several reasons for this. First, Petraeus seems to have been a skillful manipulator of his image and enjoys adulation by the press bordering on idolatry.Second, Petraeus probably did favors for some of these individuals, perhaps providing them with access to otherwise unavailable information from time to time.Third, even as a private citizen, Petraeus will powerful. People in positions of authority will listen to him, given his reputation, justified or not, and he will continue to have access to information unavailable to the rest of us through his own channels of communication. Journalists and others have every reason to cultivate his goodwill at this point, despite his resignation.