I read a book a while back and I can't remember the title. The only thing I remember are that a spaceship crashed on a (war) planet where every living thing was destroyed in a planetary war except robots who are the only things left on the planet. They nurse the protagonist back to health. There may be other survivors in the crashed spaceship. The planet was inside a nebulae and the inhabitants of the planet waged war on themselves because they couldn't see any other stars outside of the nebulae so they believed they were alone in the universe, they never had the need to explore.