> it conceives of every civilization in the universe as a hunter hiding in a moonless woodland, listening for the first rustlings of a rival.
How about
> it conceives of every civilization in the universe as a hunter hiding in a moonless woodland, listening for the first rustlings of another. The hunters are strangers who do not trust each other (or even have a language in common), so can respond with long dangerous negotiations to establish good intent, or with a swift bullet. Everyone knows this, and acts accordingly. The stable state is pre-emptive strikes, zero trust, maximum hostility.