What exactly is O. Henry's "The World Citizen in the Cafe" about?

What exactly is O. Henry's "The Cosmopolitan of the Café" talking about? I'm not sure if I understood it correctly. If it is merely saying that "world citizens boast about their own worldliness, turn a blind eye to others' disputes over national borders, territories, and races, yet cannot tolerate any criticism of their hometown, no matter how slight,"...