In this letter I will make clear what is the main concern within political sciences. Since I am not educated, I will make it plain and simple, and suggest commonness is.
In political science there are two ways acknowledged to create the feeling of ”us” as both distinctive from “not us” and distinctive from “else”. One is the habitation, that is expressions of uniformity and pride. The other is protection, against violation to the culture. The two most often come in conflict with each other. For example, when the Norwegian constitution was established in 1814, one party wanted to establish the prime law whatever cost. The other party wanted to know what foreign powers had in mind. Even so, one of the two, history shows, are made prominent in establishing cultures, within nations, more or less successfully. For instance, bairbaiting was a popular public amusement, for a while, in Great Britain and in America. Those theater like shows unified people, and strengthened the ties in the culture, it was thought. Before that, we have the theatre like shows in ancient Rome, where gladiators, for instance, fought each other. Today, football (soccer), in particular, play this role of uniting the masses. In the other way, we have this feeling of defence. One establishes an enemy to the culture. We know how this works from times just below us. The cold war is a typical example. And even worse; the Nazi German regime tried to establish both regards. They persecuted the Jew, to strengthen the inside, and they went to war against other nations, to strengthen the outside scope.
What happens to a nation establishing such embarrassment is failure. Either it is fought down by foreign powers, or the borders vanish, due to whatever reason. Bearbaiting disappeared, for example, as show uniting, both in Great Britain and in what became the U.S.A. One might point to education as the sole reason. Borders collapsed.
What to do to unite a people is of course not this. What to think of, is how to establish cultural pride, as the same time creating curiosity of what foreign is.