With the recent injury to Paul George, there seems to be a growing sentiment that international play during the off season is something that teams are going to curtail in the future, but so the cons outweigh the pros?
For young players especially, this is a great way to learn how to win. They get to play with the best players (CP3, KD, LBJ, Kobe) and they get to pick up the habits that make these players great and are submerged in a winning culture.
They likewise keep their game sharp and get to work on their shooting, and might even be able to bring something new back to their team, or even bring some plays back that could help the team.
There has been an issue with some players coming back 'out of shape' (I won't name names here), but international play could help keep these guys in game shape and in pique condition.
The con is that they might get injured or be tired, but really, if the player is good he's going to be playing competitive basketball all summer. They will likely work on conditioning and shooting and play competitively only a couple of times a week, but these guys HAVE to play and exercise to stay in the kind of condition that requires them to play at an elite level, and they frankly can just as easily get injured while running as they can while playing basketball. So the risk of injury or getting tired part way through the season seems like balderdash to me.
For me, the pros far outweigh the cons, but I'm curious what everybody else thinks about this.