True, but countries are not celestial objects, but man made entities. Each has its own laws and societal expectations. So it has to be a two way thing when we come to integration. We have to be compassionate and understanding of each others cultures, but this is sometimes almost impossible.

We have to be compassionate and understanding of each others cultures, but this is sometimes almost impossible.

Right!
And from my point of view: if only one person on whole world is compassionate and understanding than in principle every single person on the world can be compassionate and understanding. This simply can become omnipresent as basic part of human culture; as momentarily is not (yet?).