There are monsters. Otherwise, the southwest is not exactly the most lively in terms of human politics.
There's hardly any in D'Hara. Which is a blessing, as our military isn't really the most fearsome on the continent.
There's a great advantage to having a linear island realm: no foreign region borders us except via our fortified regions, which themselves connect mostly to other fortified regions. Monsters could come from the east more, but they rarely do. Mind you, last time they did, we basically lost everything we had there.