Silence.
"I'm a historian," Tom continued, "and I know that a civilization can't exist in a vacuum. If outsiders don't conquer it, it'll rot from within. It's happened to Babylonia, Greece, Rome, China, even. Over and again. The Soviets built an Iron Curtain around themselves, and wiped themselves out because of it.
"Don't you see, Jason? There are only two types of animals on this planet: the gamblers and the extinct. It won't be easy to live with the outsiders, there'll be problems of every type. But the alternative is decay and destruction. You've got to take the chance, if you don't you're dead."
A long silence. Finally Jason said, "You've only got about a half-hour's worth of oxygen left. Will you tow the satellite into the proper position?"
Tom stared at the planet unseeingly. "Yes," he mumbled.
"I'll have to check some calculations with the astronomers," Jason's voice buzzed flatly in his earphones.
A background murmur, scarcely audible over the crackling static.
Then Ruth's voice broke through, "Tom, Tom, you can't do this! You won't be able to get back!"
"I know," he said, as he started pulling his way along the lifeline back to the ship.