Just adding to people mentioning it depends what you mean by politics. Politics pretty much applies to any interactions in a group of people. You can have office politics and family politics and even non democracies still have politics. It pretty much encompasses any interactions where people are trying to get their way or their favored way within a group. Groups can be any size. International politics is pretty much looking at countries as entities and the group is the globe. Very often when something or someone is called a pariah its because they have basically withdrawn or been kicked out of political interaction.