Star Guard — Andre Norton

They were Terrans, considered by Central Control to be the ideal mercenaries of the galaxy. Divided into "Hordes" and "Legions," the former serving on primitive worlds with hand weapons, the latter indulging in technical warfare on more advanced planets. These men of death followed orders perfectly -- until rumors of whole unit annihilations began to spread.

Kana Karr was just a Swordsman of an ordinary Horde. He had been sent to an unextraordinary planet to quell a common rebellion. A simple assignment -- until Kana discovered the awesome truth behind the intergalactic rumors and realized that not only his life but the fate of the whole human race was irrevocably entwined with the outcome.