A Delta Quadrant power that conquered planets without a fight by bombarding them with disguised asteroids until the inhabitants evacuated, a tactic uncovered on a Nezu colony in 2373.
The Etanian Order is the hidden aggressor in the Voyager episode Rise. Its method is to hurl artificial asteroids at an inhabited world, made to look like a natural bombardment, and then to move in and claim the planet once its people have fled.
Voyager is helping a Nezu colony suffering just such a rain of impacts when its crew notice that the asteroids do not break up as they should. A Nezu scientist, Doctor Vatm, has found proof of the scheme inside one of them, and is murdered for it.
Tuvok and Neelix, stranded on the surface, ride an orbital tether carriage up through the atmosphere with the evidence. They discover that the Nezu official Sklar is an Etanian agent. Armed with the data, Voyager is able to drive off the Etanian ships when they arrive.