The Killing Fields, by Loren L. Coleman, is the second book in The Capellan Solution duology. It covers the last year of the Capellan-St. Ives War and its monstrous conclusion.
From the back cover
|| In hope of salvaging the embattled worlds of the renegade St. Ives Compact, Chancellor Sun-Tzu Liao has launched a war that stretches far beyond the scope of military conquest. His mission: reunite St. Ives with his own Capellan Confederation. But after months of combat extend into years, the smash-and-destroy tactics have turned the crippled Compact into a bloody wasteland—and the Chancellor's costly victory into a virtual deathwatch.
For the warriors of House Hiritsu, and for the Capellan and Compact soldiers on the 'Mech-shredded front lines Sun-Tzu's noble crusade has become a nightmare. And now, with his dream of glory slipping away, the Chancellor will make one last desperate gamble—a final solution to regain total control of a civil war exploding out of control. No matter what the cost.