Windaria (1986) IMDb
Unicorns graze as a high-tech dirigible gathers ghosts in the distant sky. An idyllic village lies between one extensively industrialized amoral nation and one pre-industrial but flourishing and peaceful nation (whose capital is built a good four metres or so beneath sea level, right by the ocean!). Uninformed jealousy spirals into paranoid war, despite the best intentions of a prince and princess on opposite sides. Simultaneously, a young husband from the idyllic village seeks excitement and adventure, finding it without realizing the cost.
Tragic fantasy parable. Not credible, but it has some nice tragic deconstruction, and a couple of good songs. Original title: Douwa meita senshi Windaria (literally “Windaria: Fairytale Warriors” in the past tense).