I'm trying to find the name of a sci-fi book I read in the 80's. It's about some mercenaries who go to planets and sell advanced weaponry to warring parties. They arrive on a planet of masters and slaves. The masters eat the slaves babies as a rite of passage and have sharpened teeth.
"The Men in the Jungle" by Norman Spinrad.
All his life, Fraden had been in control, had bent situations, conditions, people, to his own will. He had stood solidly, reaching out to change men and events, but had never been changed by them. He had been booted out of Greater New York, he had taken and lost the Asteroid Belt, and he was still the same Bart Fraden. But on Sangre... something had been done to him. He had been tampered with. For the first time in his life, Bart Fraden felt himself moved by forces beyond his conscious control. Had he changed Sangre? Or had the planet changed him? For the first time in his life, Bart Fraden was afraid.
Credit to Emsley Wyatt for finding the answer.