Language is necessary to live in any place. I won't argue with that. You could move to France and then learn French if have enough money to stay long enough without a job.
But I think there is more to your nationality than just a language.
Take me as an example. I am fluent in both Chinese and German. I look Chinese, like both countries food and grew up in a mix of both cultures. I don't even know what my nationality is (officially it's Chinese, though). I have also have passports from both countries.
But is language enough to be fully integrated? Do you have to be foreign to be not integrated?
Maybe being foreign and being integrated are to separate things?