War never changes. It's still one of the most expensive activities humanity has come up with. Even anime that depicts war tend to have expensive problems. One can't make an anime about war but skimp out on the action, after all, and animating large-scale action is costly. Consequently, that's also likely one of the reasons why war anime are rare. At least, they are rare when compared to other genres that don't necessitate too many action sequences and spectacular moments. That's why war anime needs to be cherished and appreciated as they appear. One will want to start with the best of them, however.