Just a quick comment to the majority of posters on this thread.
You talk as if history ended when Western civilization (or whites, as you imply) achieved supremacy. If the world becomes a little browner, as people migrate around the globe,why do you assume that your culture will disappear?
I have friends that are ethnic African, Chinese, Hispanic, etc. Their parents have accents and observe their native customs, but their kids are just as American as I am. They speak like I do, have the same interests, root for the same sports teams, and watch the same movies I do. Aren't they part of Western culture?
It's estimated that by 2045, whites will no longer be in the majority in the US. They will still be the largest minority. I suspect that they and the children of immigrants will be pretty much what they are today. Americans.
Do you have so little faith in your cultural identity, that you think it can't withstand exposure to other cultures. That doesn't reflect well on your faith in your superiority.
The solution is simple. Only marry other whites, and have large families. Try to convince your children to only marry other whites (good luck with that!).
The rest of us will enjoy life, and the incredible experiences, foods, traditions, handiwork, and people of this world.
I hope for their sake your children aren't as fearful of change as you are.