Yes, the NBA should expand to Europe, because that would promote the sport of basketball and make it popular in Europe. More people would have a chance to play in the NBA, and the level of the sport would increase. It would also be an important way to exchange cultures with those living in Europe.
No, the NBA should not expand into Europe, because it would cheapen the game. It would be too hard on players to go to Europe to play. Europe also does not have the fan based that the United States does. The game will never be as popular there. With more players, the level of play will also go down.