“There’s no way out,” Jim says, despair filling him.

“Maybe not. But I do what I can.”

He looks away from Jim, down at the concrete of the driveway.

“But I can only do what I can,” he says hoarsely. The corners of his mouth tighten bitterly. “I can’t change the way the world is, and neither can you.”

“But we can try! If everyone tried—”

“If pigs had wings, they’d fly. Be realistic.”

“I am being realistic. It’s a business, it’s using up an immense amount of resources to no purpose. It’s corrupt!”

Dennis looks down into the motor compartment, picks up the wrench, turns it over. Inspects it closely. His jaw muscles are bunching rhythmically, he looks like he’s having trouble swallowing. Something Jim has said …

“Don’t you try to tell me about corruption,” he says in a low voice. “I know more than you’ll ever imagine about that. But that’s not the system.”

“It is the system, precisely the system!”

Dennis only shakes his head, still staring at the wrench. “The system is there to be used for good or bad. And it’s not all that bad. Not by itself.”

“But it is!” Jim has the sinking feeling you get when you are losing an argument, the feeling that your opponent is using rational arguments while you are relying on the force of emotion; and as people usually do in that situation, Jim ups the emotional gain, goes right to the heart of his case: “Dad, the world is starving.”

“I know that,” Dennis says very slowly, very patiently. “The world is on the brink of a catastrophic breakdown. You think I haven’t noticed?”

He sighs, looks at the motor. “But I’ve become convinced … I think, now, that one of the strongest deterrents to that breakdown is the power of the United States. We can scare a lot of wars away. But up till now most of our scare power has been nuclear, see, and using it would end us all. So little wars keep breaking out because the people who start them know that we won’t destroy the whole world to stop them. So if … if we could make the deterrent more precise, see—a kind of unstoppable surgical strike that could focus all its destructiveness on invading armies, and only on them—then we could dismantle the nuclear threat. We wouldn’t need it because we’d have the deterrent in another form, a safer form.

“So”—he looks up at Jim, looks him right in the eye—“so as far as I’m concerned, I’m doing the work that is most likely to free people from the threat of nuclear war. Now what”—voice straining—“what better work could there be?”

He looks away.

“It was a good program.”