we could cut a deal or something:
Allegory:
Yeerks=America/Spain
Andalites=British
Humans=Africa.
we could fight our crazy tribal wars with each other, the loser gets captured and sold to the yeerks for the equivalent of glass beads/AIDS vaccine/new ways to kill people etc. Then the Andalites would try and police this trade and save the human race from selling itself into slavery and colonise our planet the way the brits did to africa a veritable male Andalites burden.
Or we could sell the Yeerks our mentally ill, retards who are still physically fit, criminals and welfare dependents and thus avoid turning into idiocracy.