Yes, there are a growing number of foreign players making a name for themselves and sticking with teams in the league. But, somehow I still don't have the impression that a NBA team has played another country's best unless during the Olympics which is an entirely different topic. Because a gold medal winning Olympics team could rightfully so boast of being the best basketball team in the world until the next competition. Then that distinction could change hands.
I always have wondered this but never really thought to search out an answer online thinking I wouldn't find a concrete reason.
I'm searching around and looks like Euro basketball uses "World" in some of their tournament names as well. Now I really don't get it. All of these teams across the globe (or where ever professional basketball exist) haven't competed against everyone on the planet.

I could be reading it too literally. But, how can you not? It says, world... As in, in the world.