From the back cover Del Ray paperback July 1993:

LOYALTY DIVIDED

Mars was harsh, arid, and unforgiving, but for the colonists who called it home, its future was as bright as the comets that hung in the night sky. The comets were the hope of Mars's rebirth, corralled by the miners of the Mars Project from the vast Oort Cloud beyond Pluto -- for locked in those icy bodies were the water and gases that would make Mars green.

Young Dekker DeWoe yearned to become an Oort miner. But when he finally arrived on Earth to begin training, he was suddenly confronted with the looming death of his dream. The backers of the Mars Project were threatening to shut down Oort mining in favor of the money to be made in Earth's new orbital farm habitats, and only the nonviolence of his Martian upbringing helped Dekker to control his frustration over the fate of his homeworld.

Then he began to hear rumors of a secret plan to force the restoration of the Mars Project. But the rumored plan would soon place Dekker in an impossible dilemma -- for its success meant the deaths of millions, and failure meant the death of his beloved Mars...