Recon: The Complete Series

Tyler Callas had a life most people would kill for; he killed to escape it.

Tyler is the pampered scion of one of the ruling families of the Corporate Council, the legal monopoly that runs the human Commonwealth. His mother has his life planned out, with a seat by her side, running the conglomerate.
Tyler has other ideas. With the help of a great-grandfather who was a United States Marine when there used to be a United States, Tyler changes his face and his identity, becoming Randall Munroe and enlisting in the Fleet Marine Corps, qualifying for the point of the sword, Force Recon.
Plunged into an interstellar war against the relentless Tahni Empire, Munroe is stranded alone on an occupied colony and forced to organize a civilian resistance to the enemy. The year of constant violence and death wears him down, yet sharpens him at the same time.
After the war, Munroe once again takes up arms, this time against his will, when his uncle, Andre Damiani, the head of the Corporate Council, blackmails him into leading a special squad of trouble-shooters, eliminating threats to Council business among the criminal cabals in the Pirate Worlds.
But the real enemy is still the Council, and Munroe vows to take the fight to them, no matter what the cost.

The full collection of all four books in the mil-SF RECON series:
A War to the Knife
A Wolf in the Fold
A Battle for the Gods
A Fight to the Death