I'm specifically referring to CIA deputy chief John Redmond from the fourth season of Homeland, but this jowly, seen-it-all breed thrives in other guises. They could also very well be a reporter (maybe a photographer?) and are definitely divorced, probably with grown kids. All that matters is that they are escaping something, are probably smart or at least went to a good school, a little belligerent, and might be fun for a drunken fling if for some reason you found yourself in a dangerous part of the world, fueled more by adrenaline than rationality and long-term planning. By the time you got bored or came to your senses, one of you might be dead anyway.
Somehow I feel like Vincent D'Onofrio fits into this rubric, though I can't think of a concrete example (and I defnitely don't mean the spoken word punk D'Onofrio).