"Originally, that civilization, after winning, would have just continued mining. Even if they dug out all the minerals from the earth's interior, it would have no impact on the creatures living on the Earth's surface. However, the star-condensed substance on your earth is buried very deep. With the present state of those metallic monsters, it's impossible for them to quickly excavate all the star-condensed substance! Hence, they need a huge communication device, to call back the exploration spaceship that has been away for more than 300 years! Before that, since there are living creatures on the earth's surface, it will certainly hinder future mining operations. Therefore, they must undertake another task - Life eradication, where they eliminate all life forms on Earth! Hence, the current war on Earth's surface ensued."
"As for my civilization, and the other one, my civilization advocates peace. We don't want to see all life on Earth die, but we are powerless to stop them."
