I assume it would usually be for serious violations, like theft or security issues.
When the military decides to bring someone back to prosecute them they tend to keep it quiet so it is hard to know when they are likely to do it but they did recall and charge a retired two star General in 1999 for adultery. I read about it just a few minutes ago but his name was not in the article I read so I don’t know the circumstances. That General was charged with two charges that he committed adultery with wives of subordinate officers. I was told there is an active duty General being tried right now for adultery but don’t know the circumstances of that either.
I think if Obama wants Petraeus prosecuted by the military he will be and if not then it won’t happen. Under normal circumstances I would doubt the military would do it just for adultery alone.
Another issue Petraeus may face is according to some reports classified documents were found on Broadwell’s computer by the FBI. Petraeus has stated he did not supply her with those documents. It is not clear whether the documents in question were from the time frame of when he was in the military or if they are documents he may have had access to as CIA director. If the documents are from the military and it seems likely they did come from him then I would think it would be more likely he could face prosecution by the military and then possible adultery and other charges would be included.
This seems to be quite a mess unfolding, and who knows how much we are getting from the media is true? Who knows if there is more to come or how this will play out? Who knows if Obama will protect Petraeus or throw him under the bus?
I do think as the Benghazi investigation unfolds we need to keep all this in mind. I see the affair as a distraction to the investigation right now, but as it plays out it could impact what Petraeus chooses to testify to or how we should judge the truthfulness of his answers considering the rest of his issues.