This is from a book I read in the early to mid 1990s but no longer remember the name of. I believe I checked it out of the school library, so it was probably a young adult novel.
The story opens on a remote pleasure/vacation planet which is shocked by the appearance of a damaged and derelict battleship appearing in its star system. After some time the planet decides to recover and repair the ship and go see where it came from. In the course of their investigation it is revealed that there was a large interstellar war. That is all I remember of the book.