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If aliens do come it may be only cause they want us on thier side of some bigger war.
(self.showerthoughts)
A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. A showerthought should offer a unique perspective on an ordinary part of life.
Footfall nails this. Aliens show up and drop rocks on us from orbit. The reason we prevail is the only plot I've read that makes sense.
How To Beat Aliens
They didn't invent the ships or tech they're riding in and aren't much, if at all, more advanced than us. Plus, we figure out their rigid social hierarchy and turn it on them. Also, we nuked Kansas.