a one to one correlation between country and league. There are leagues in Spain, France, Greece, and Russia. There's also an Adriatic league that has clubs in nations along the Adriatic Sea. Every year, the top clubs from each league will compete in a Euro tournament against the top teams from the other leagues. So teams compete in their own league, and if they are good enough, compete in the Euro league.

I'm hoping that the NBA starts participating at a club level in FIBA tournaments in the future. I think it would be really cool to do a club world cup, similar to the one that is done in soccer. Take the NBA conference finalists and put them in a single elimination tournament with the top 4 teams from Europe, and the top 4 teams from Asia/Pacific.