Imo, the problem isn't that cultures influence other cultures, but the speed at which this now happens. I like many parts of American culture but I don't think that it should be the only culture. For a smaller group to develop and preserve its identity, it needs time and some amount of isolation. Not sure how this could happen in the modern world, but wouldn't it be great to be able to go somewhere and see people with different scientific ideas, art, technology, philosophy etc?