Surely the Terran empire did it many times. And the ship was supposed to be more or less equivalent.
The logic seems pretty clear.
Point 1) Vaal was trying to destroy the enterprise, attempts at negotiating failed due to its total refuse to negotiate;
Point 2) Vaal had been keeping its subjects as slaves, barring them any form of development or free will, for thousands of years.
Ergo: Vaal needed to be stopped.
Not what I'm talking about. I was referring to the plot logic rather than the story, of course. The progress of events is arbitrary and preposterous.
Terrible show all around.