I've made this post before, but the only solution I see is turning the entire planet, it's populace and biosphere into a massive hostage situation. Plant every nuke we have across the surface of the planet, beneath cities, nature preserves, the jungles and forests and natural wonders, everywhere. Then make it very clear that if the ayys try anything funny the little blue planet gets it.

Does this rely on the ayys wanting Earth intact? Sure, but if they don't care we're totally fucked anyways.