This post, while following on from the last one, will be addressing a bit more of a broad problem across genres. It’s gotten a lot more talk in the science fiction and fantasy genres (particularly fantasy) than it has in the thriller genre, but it still applies.
The fantasy version of this has been most recently highlighted by the work of George R.R. Martin, though there are plenty of authors working along a similar vein, which has been coined “grimdark,” a term that became at first something of a joke, based on the tag-line for the Warhammer 40,000 tabletop sci-fantasy wargame: “In the grim darkness of the far future, there is only war.” Taken to its extreme, it can become so ludicrous that it shades into “grimderp.”
The basics of “grimdark” is that everyone’s an asshole, life sucks, any victories are defeats in disguise, heroes are dupes, and only anti-heroes have a snowball’s chance in hell of success, though it would be better to be a villain. Endings where the bad guys win, or the good guys’ (if there really are any such) victory turns out to be hollow, are considered “good” endings by this model.
This is, of course, a very basic rundown. There are various shades across the spectrum; the Praetorian series would probably count as “grimdark” by some of the above rubrics (though I’ve tried to include good guys along the way; not everybody’s an asshole).
The problem is that this gets passed of as “realism,” when in reality, it’s not. And the thriller genre is as full of it as the SF/F genres. How many thriller heroes are more anti-heroes, ruthlessly doing “what needs to be done?” (Yes, I’m aware that Jeff Stone is pretty close to that archetype. And he’s going to be doing some soul-searching about it in Lex Talionis. Dan Tackett, however, I would argue is not.)
The Praetorian series is as dark and bleak as it is because it comes out of a particular set of circumstances, i.e., the general failure of the GWOT, and the chaos that it’s left behind. There aren’t a lot of happy thoughts going through a veteran’s head when he’s reading the news and seeing places that he patrolled through and fought over, maybe even made friends with some of the locals in (Yes, it did happen. Iraq as a whole might be a shithole, but there were plenty of the villagers who welcomed us, fed us, and begged us to protect them.), being taken by ISIS (or whoever the successor Sunni insurgency turns out to be), or the Taliban, or some similar batch of bastards. But even so, nothing is ever 100% dark all the time, and not everybody is an asshole.
One of the greatest Recon Marines I ever knew, whose funeral I unfortunately had to attend in 2012, was also one of the greatest men I’ve ever known. Not only was Dan Honor Graduate in every course he ever went to, but I can’t remember a time where he was ever surly or genuinely mean (aside from the usual team-room shit-talking that goes hand-in-hand with the profession). While he was good at what he did, and took justifiable pride in it, he was, rather like Steve Rogers, “a good man.”
A better-known example would be Maj. Dick Winters, of Band of Brothers fame. By all accounts, not only was Maj. Winters an outstanding combat leader, he was also a thoroughly decent man.
Some would argue that, say, Martin’s crapsack world of “A Song of Ice and Fire,” better known to TV viewers as “Game of Thrones” is more realistic in regards to the Middle Ages. Except that that doesn’t fit, either, when there were knights such as Bayard who were equally respected for their courtesy and nobility by friend and foe alike.
None of this should be taken as advocating for Pollyanism. Too often in thrillers we find the opposite problem, where the nuke is stopped, the day is saved, and everything goes back to normal. Violence has consequences, and especially plots to blow up tens of thousands of civilians with weapons of mass destruction have repercussions. Even the generally more personal violence found in heroic fantasy, or smaller-scale thrillers, has repercussions. It is brutal, painful, and life-altering when it isn’t life-ending. It shouldn’t be taken lightly.
The point is that there’s a balance. You are trying to tell a story. Justifying a cast made up entirely of unlikable characters doing nasty things to each other with no real conclusion isn’t “realistic.” It’s lazy storytelling.