I'd heard some good things about this author, so I decided to give one of his books a try. I don't know if GREATEST ENEMY is Jason Kasper's first novel, but it's the first book in his American Mercenary series, so I figured that might be a good place to start.
The narrator/protagonist, David Rivers, is a former soldier, a veteran of Iraq and Afghanistan, who, after going through West Point to become an officer, abruptly finds himself out of the army due to a medical condition he didn't even know he had. At loose ends, Rivers retreats into drinking and extreme activities like BASE jumping to fill the sudden void in his life. As it turns out, Rivers isn't really very stable, mentally. But he is really good at what he does, as he finds out when he's recruited to be part of an elite special operations team.
No, he doesn't go to work for the government, as you might be thinking right now. Instead, he works for some shadowy organization that's at war with a group of other shadowy organizations. That's right. These are bad guys. In fact, there are no real heroes in GREATEST ENEMY, just bad guys . . . and worse guys.
I'm not normally a fan of novels with criminal protagonists, although in the past I've really enjoyed Donald Westlake's Parker novels and the two most famous hitman series, Lawrence Block's Keller and Max Allan Collins' Quarry. It's hard to write about unsympathetic characters and make the reader root for and care about them. Jason Kasper walks that fine line here, and for the most part, he succeeds quite well. David Rivers may not be a very likable guy, but he is a very complex and well-realized character. There are also plenty of really well-written and exciting action scenes, the book is fast-paced, and as an added bonus, it's a good length, not one of the bloated doorstops that often pass for thrillers these days.
One word of warning, however: GREATEST ENEMY ends on a semi-cliffhanger, which actually works pretty well because it's obvious that this is just part one of a larger story. There's enough resolution that I didn't feel unsatisfied, and enough still to come that I'm eager to read the next book. Which I already have on my Kindle, by the way.