Human nature always requires that (1) we belong to identifiable groupings { English, Saints fans, protestant, etc ), and (2) that there is always somebody we can look down on and determine as being inferior { the French, Skates, etc }. Every country in the world is an artificial historical construct, it's just that some have been around longer than others. The UK didn't exist before 1801, Great Britain didn't exist before the Act of Union, England as a united entity within it's currently defined borders didn't exist when William the Conqueror invaded.
The only common unifying factor is that we are all , ( regardless of creed, colour, size, IQ, sexuality, or religion ), members of a single species inhabiting a single planet.