I don't think most people do sports to cultivate friendship in the world as many people here are suggesting. People to sports to test their limits, to see how good they can get at something. They start to wonder, "Maybe I'm the best in my town?" Then they organize a competition in their town to see who's the best. Then this grows to a state/regional/provincial level, then a national level. At some point, a sport get popular enough in the world that a couple countries get together and decide to see whose country is best. At some point you get events like the Olympics or the Pan-Am games, where an organization decides to gather many sports together and see whose country is best. I think the main reason for the organization of it all is financial gain.