Paying the Piper — David Drake

When the tariff dispute on Plattner's World exploded into war, the United Cities hired the best mercenaries money could buy:

HAMMER'S SLAMMERS

Lt. Arne Huber was old enough to be a veteran but still young enough to have principles. From his first minutes on Plattner's World, he was in the middle of hot, flaming war. He knew that wasn't going to change until the Slammers either left the planet or his relatives back on Friesland got a coffin with a warning to bury it unopened.

Huber and his platoon had to face government officials with private agendas, politicians with armies of street thugs, and a hostile armored division with the most powerful tanks on the planet. The climax would come as it always did, when the Slammers slugged it out, and tank cannon, automatic weapons, and the world-shattering thunder of massed artillery would turn the night into an inferno and a slaughterhouse.

Arne Huber and his troopers knew they could die, because they'd watched friends die on every planet where they'd served. Maybe they could even be beaten--

BUT NOBODY'S BEATEN THE SLAMMERS YET!