Ready the Terraformers

SETI received a message from an alien intelligence—the world rejoiced.

The aliens offered replicator technology:

"We're providing you our technology to protect your species. Soon, you'll encounter the Vagols, a sinister interstellar species that traverse wormholes to invade civilizations. We suggest using the replicators by preparing to defend yourselves. There's no limit to what you can make."

Decades later …

"What's Earth's progress?" asked an alien commander.

"They're nearing total extinction, as we've planned, sir. They couldn't help but produce the fiercest weapons against one another. But, of course, that leads to their inevitable self-destruction."

"Excellent! Ready the terraformers."