Earlier quoted context omitted.
I'd expand that to cultural preservation in general. The French like being French and living in a French country, with all that entails concerning values, music, food, and way of life. The Japanese like being Japanese and living in a Japanese country. Mass migration can change the character of a country. It's totally logical to want to preserve your culture and way of life. If 100 million people from the Middle East…
This will be controversial, but France doesn't have any right to be a "French" country. Individuals have rights, but cultures and nations don't have a right to exist. If they did we would be obliged to preserve them, but peoples, countries and cultures always vanish over time, and there's no general obligation to stop this happening. Saying otherwise is simply a conservative demand, with no ethical basis. "The French…
The fact that everything dies in the long run doesn't mean that those who hold their nations and cultures dear today should not work toward their preservation. An argument from nihilism isn't convincing to me. You and I will die too, but that shouldn't stop us from pursuing the good life in the meantime.
Besides, it's not a given that all current nations and cultures will die. They will certainly change over time, but it could very well be that the first human colony in another galaxy will fly an American flag. It's unlikely, but who knows.