War trauma beyond Azur Lane's ship characters

Why would Azur Lane's commander and ordinary humanity also be traumatized?

The fictional conflict affects everyone, although the story focuses on its ship characters.

The fictional war is vast enough to traumatize humanity as well as the Kansen. Much of humanity is described as having died. Attention falls on the Kansen because the story is organized around them. The commander is understood to carry trauma while continuing the work required by the conflict.