This question comes to not every of us - why we are so divided? There are for sure many answers like:
(1) we allow to divide us (kinda cloudy answer)
(2) it is them, we want good to people only (real meaning, they do not want to agree with us)
(3) we are used (so why do you agree to be used?)
and so on. In fact those answers are trying to push off responsibility, but this also depends on the position of our interlocutor.
In my opinion one of the answers which hit into the root cause is my observation that we have less and less high-level common denominators. This is also relating to society atomization. What do I really mean?
The most obvious common denominators for nation/society are language, culture, religion, "ancestry". Let's go through every example.
Language - this concerns mainly European countries being under influence of American culture. We see that more and more words are coming from English, they are not translated but just added to vocabulary, sometimes with transphonetization. Language is being impacted by other language what increases differences between genreations (younger ones are talking in language foreign to older, even if it is theoretically the same one).
Culture - this is very similiar to language, but it works not only across generations, but also inside them.
Religion - even if Catholic religion is in decline, it is hard to disagree with statement that it played significant role in self-determination of nation. It does not mean that religion is good (this is very complicated thing) and I understand why less and less people are coming to church. Though, there is no real alternative (atheism is not an alternative in terms of being common denominator due to lack of tradition and rituals).
"Ancestry" - nations being more atomized become also more global (which seems to be self-contradictory), it is very hard reconcile idea that Germans are coming from (ancient) Germans and French are coming from Gauls, as they were different folk.
We are slowly starting living in cosmopolis, but is this really good? I am afraid that in this process we will become "one family", "one humanity" which will suppress differences and then we will become a mass, blob with no choice, no opinion. I do not encourage to saying "my nation is better than yours", but I encourage you to finding common denominator with other people. Roman empire had to "fall" and there is no real example of big united nation in the past and currently.
