Choosers of the Slain (Paladin of Shadows, Book 3) 
Former SEAL Michael Harmon (Ghost, Kildar) has a pretty good life. He's settled down in the country of Georgia and built a solid commando-quality militia out of his local retainers. The Keldara have an ancient history of being first-class mountain warriors and all they needed was a few million in modern weapons and training to bring them up to speed. Now, with the Keldara keeping the area safe from Chechen raiders, and the various other terrorists that want Ghost's head on their wall, he can settle back, relax in his harem and drink a few beers. However, a US senator has a problem. A "major financial contributor's" daughter has been kidnapped into the labyrinthian depths of the Balkans sex-slave trade. The US government has been unable to find her and the Senator is _very_ interested in changing that condition. Five million dollars interested. As Ghost and his Keldara warriors blast a gaping hole through the middle of the trade, it quickly becomes apparent that there is more to the mission than a "poor missing waif." There's a rot underneath, and the stench is coming from the very floor of the Capitol. Being at war with Albanian gangs is one thing. Taking on Washington is a different ball game. But Ghost never believed in fighting fair.
Reviews
What the Kildar books do have going for them is a reasonably-intriguing, well-thought-out if-I-were-King arc, as well as the more usual (for Ringo fare, at any rate) how-you-train-up-troops tropes.
And a certain gritty-grimy-gutsy-romantic approach to the unsavory underworld of sex-slavery, as somewhat subtly (again, folks, for military adventure/escapist fiction!) contrasted with a jaded military guy's attitude to the "traditional" sex industry, as well as his own "struggle" to control, without entirely reppressing, his own urges toward sexual dominance.
I have no particular reason to believe that Ringo's sexual underworld isn't composed of at least as much fantasy and wishful thinking as "his" vision of real-politik (which, let's admit, is not at all out-of-character for his chosen main character), but it's still an interesting new milieu to "explore." Likewise, the fictional folk-ways and ethos of his lost tribe of liege-folk.
I'm still with Ringo, here, overall, although I'd like to keep seeing each of the interesting aspects of this little exercise in world-building carried forward vigorously in part four.
I don't mind a little sex for sex's sake, or a lot of action for action's sake, but the hub of this series is Mike's interaction with the little world of quasi-medieval, Third World characters for whom he has become responsible, and how those characters develop as they are brought out into the First World from which--as much as he hates to admit it--Mike hails and of which he is, in his own warped and troglodytic way, a representative.
What I don't want to see is a lot of padding and backing-and-filling to paper over a plot that isn't developing any of the key components of our little world, however pleasant or perverse the bits of wish-fulfillment it's composed of.