The Never Ever War. The Lunar Free State, #8

"War" is a dirty word on Ragnarok. For the past hundred years, the planet's human inhabitants have been trying to rebuild their civilization after a self-inflicted nuclear holocaust. The event-which they call the "Great Destruction"-was so traumatic they've destroyed all the records and refuse to talk about it, other than to swear it will never ever happen again. At least, that's what they tell the Lunar Free State's contact team. Unfortunately, not all the inhabitants agree on what that peaceful society should look like, and their disagreement has reached the level of an armed conflict between two groups, one of which is supported by a covert ops team from the Confederated Nations of Earth.
The locals may not be willing to call it a war. but the LFS ends up in the middle of it, just the same. When a Confed Navy task force arrives to take over the planet, the LFS is forced to respond, taking the war that was never supposed to happen to the interstellar level.