A polis of ancient Greece was a a)politically independent unit that included a city and surrounding land. A polis meant the city-states which existed during ancient Greece and would stand today as what it's modern city would be called. A polis also stood as a form of identity as it would be a person's citizenship and can be used to describe a body of citizens.
Definition: Traditionally, the term "international conflict" referred to conflicts between different nation-states and conflicts between people and organizations in different nation-states.
It shows that the war resulted in a new illusion of omnipotence."In April 1917 the illusion of isolation was destroyed, America came to the end of innocence, and of the exuberant freedom of bachelor independence. That the responsibilities of world power have not made us happier is no surprise. To help ourselves manage them, we have replaced the illusion of isolation with a new illusion of omnipotence" Barbara Tuchman