Actually, the Feral Europeans infested us before they went to North America.  Our pushing 'em back--for a while--led 'em to seek alternate trade routes to the east, so you're our fault, in one respect; and even more because the Umayyads and Almohadins were so corrupt, lazy and stupid that they allowed the crazy Spaniards off their leash (who let the Catholics out?  Roof! Roof, roof, roof, roof!)  They handily defeated the sorry remnants of Muslim Spain and then swarmed the world like locusts.  Next question.