This is fairly straightforward. He is still subject to the UCMJ, under which it is a serious crime for a married officer to have an extramarital affair. Outmoded? Sure, but plenty of officers have had their careers ruined under it. Some probably did time. I haven't seen any data, but I'd be surprised if officers under Patraeus' commands hadn't been prosecuted for this in the past. So he authroized prosecution of other guys for the same thing he was doing secretly. Not even all that secretly apparently, but that's another issue. The republicans were furious at Patraeus even before this for a seriously misleading briefing he gave them on Benghazi, which apparently echoed the WH's then line that it was all about the video. He or the CIA concealed other crucial evidence as well. His treachery may be enough to break the usual fawning deference republican congressmen give to the military brass. There may be other crimes involved as well. Did he lie to the CIA or whomever did his background check before he became DCI? Surely someone asked him if he had committed any crimes or was involved in anything that could lead to blackmail. Lying on this stuff would be a crime for sure, so it's not just a matter of going after a retired officer for something that happened during his service. I'm still waiting to hear how it was discovered, by whom and most importantly, when. All legitimate matters for congressional inquiry.