They didn't exactly hold a gun at anybody's head; all they offered was help. Of course, they did sort of encourage people to ask for help....
pears packed a lethal jolt. Probably, he thought, a rumor of the poor fisher folk who worked the southern fringe areas. What else could you expect from such types, who had never even learned to read in a thousand cycles. Nevertheless, as he patrolled the sunken rocks, he was alert, scanning the water on all sides constantly for the great shape he sought, his skin alert for the first strange vibration. By neglecting the broken bottom, brown with laminaria and kelp, he missed the great, mottled tentacle which plucked him off his torpedo in a flash of movement, leaving the riderless craft to cruise aimlessly away into the distance.
"Your highness," said the Supervisor Supreme, "we are helpless. We have never used metal nets, because we have never had to. Our fiber nets they slash to ribbons. They attack every species of food-fish from the Ursaa to the Krad. The breeding rate is fantastic, and now my equal who controls the mines says they are attacking the miners despite all the protection he can give them
A race of reptiles on Mureess is a little too arrogant in its view of the universe to be a good fit with the Sirian Combine, but the Combine had to ask. After all, they had atomic power, and soon, spaceflight.
The story is fairly well written, the characters consist of people of different (stellar) races, the plotting moves along well. I'm not sure the means the Combine uses would result in the ends the story suggests. Evidently they didn't in five cases.