Into the Ruins

Publisher's blurb:

The dwarves, greedy and isolationist, considered the other races as enemies. Everyone was plotting to steal their wealth. So they went to war to drive the other races back. The made many enemies, fought on many fronts, and found themselves in a bad spot. They turned to the demons. The dwarves had some dealings with throughout their history and knew demons did not like the other races either. The dwarves target demons with known hostilities toward the elves and humans, allied with them and struck farther into the lands of humans and elves.

Their alliance with demons only fortified the other races to work together. It did not take long for the moral of dwarf and demon to break. They battled amongst themselves. And lost.