The First World War was supposed to be the war to end all wars. It ended nothing. The men who fought in it were called the Lost Generation- because even those who weren't killed were different when they returned.
Every world, realm and race of life knows what war is. They know pain, loss, regret and hope. Some live their whole lives without ever seeing the end of the war that plagues their world. Some see the end just in time; some see the beginning and thank the gods that they won't be around for the worst of it.