Agloco, I only quote your post because of the part I've bolded that always winds up in these debates. I appreciate posts like yours that try to make a point without personal attacks.
As to contractual obligations; all NBA teams and players are subject to the provisions of the CBA. Under the CBA, the owners get limits on players salaries, rookie pay scales, and other things that protect their interests. The players get guaranteed contracts and many other benefits. The CBA prohibits certain behavior and allows teams to seek remedies in the case of violations (Monta Ellis, Vladimir Radmanovic, for ex).
The CBA specifically protects the players right to play for their National Teams as long as certain insurability issues are addressed. Beyond that, the NBA actively promotes and markets the participation of its players. The NBA is an active partner in the financing, training, coaching and marketing of USA Basketball.
I have no problem with any NBA player participating for their national teams.
I also have no problem with a team doing what the Spurs with Manu last summer and withholding a contract extension to wait and see what the effects of such participation may be on a player's future contributions to the team.
If NBA owners want additional control over National Team play, they should negotiate it into the next CBA.