The "Clone" of the title obviously refers to those replaceable parts, the soldiers themselves. "Republic" is a bit more complicated. Yes, the Unified Authority now ruling Earth and the galactic colonies includes a representative government element, but "Republic" really refers to Plato's famous work by that name, from which the perfect military model is derived, including the one key little lie that makes it all work.

Parentless Wayson Harris has been raised in one of the orphanages that are primarily development centers for young clones not yet of service age. He's among them, but not one of them. He looks different, thinks differently, and the gulf only widens when he finally becomes a soldier himself. Those differences are bringing him promotion with unprecedented speed, but are also bringing unwanted attention from multiple sources that could prove fatal. He's just another soldier, so why do so many people seem interested in him and what can he do about it before his existence is no longer an issue for them?

There's enough intense action to satisfy any military SF fan. And while there's some cliché and predictability about the characters and story, there's also a believable plot and enough humanity to raise this several steps above being just the prose version of a game of Doom ® or Half Life ®, as so much military SF today seems to be. I'm not good enough at fighting and battle tactics myself to credibly evaluate them, but they ring true, as do the other aspects of military life. And to cap it off, the writing flows very nicely to make this the smooth, quick read an adventure story such as this should be. An enjoyable military adventure in an all-too-believable future.