Perhaps you don't understand the political dynamics of our advanced neighbours. They won't attack, just as they never have. They have a highly evolved understanding of spirituality. A scientific understanding of it, if you will. Where we have a few dusty old books to interpret, they moved past that long ago.

Like us discovering a higgs-boson in a big machine, they discovered "soul" particles. What they are, how they interact with a myriad of other subatomic particles we have yet to theorize on. That knowledge didn't exactly kill their religions, but bolster their faith in how amazing the deity is.

In short, they know what imbalance a genocide would create. They would never perpetuate it. At the same time: they wouldn't stop us from destroying ourselves.