First off, congratulations to Spain on their gold medal win over Greece. Second, I got a chance to watch the USA-Greece game last evening before heading out and having seen it, the precise manner of Team USA's loss makes it rather than surprising than one might have thought. In essence, as some people told me in comments, the Americans did a poor job of defending the pick and roll while the Greek team was clearly having an "on" night and executed brilliantly in terms of making sure to hit their open shots.
The thing of it is that when you get right down to it, when one looks at a collection of talent like Howard, Bosh, Brand, James, Anthony, Wade, Johnson, Jamison, Battier, etc. and feels inclined to proclaim them "the best collection of players in the world" what you aren't saying to yourself is "damn! those guys are going to be great at defending the pick and roll." Indeed, of the twelve players for Team USA exactly zero of them have ever made an All-Defense Team. Now, Shane Battier actually is an extremely good defender and there's a very credible case to be made that picking him over Bruce Bowen for the role of perimeter stopper was the right call and that Bowen is enjoying an outdated repuational advantage.
But still, even a stand-out perimeter stopper isn't really what was at issue here. Rather, the difficulty was the elusive team defense -- probably the least-understood and hardest-to-quantify aspect of the game. Still, even though it would have been difficult to select for team defense, USA Basketball clearly didn't really try. If you look at the opponent statistics table here you'll see that Team USA's roster contained exactly one guy who played on a top-five team in terms of defensive efficiency -- Battier. Hinrich, Brand, and Wade play for teams in the 6-10 bracket. Four guys -- Bosh, Howard, Johnson, and Jamison -- were from bottom-ten teams in terms of efficiency.
Now on some level, I find it a bit hard to blame the program for this. The best famous defensive big men -- Wallace, Duncan, Garnett -- didn't want to play, and getting young-and-talented guys like Bosh and Howard involved in the program seems reasonable. At the same time, it's genuinely hard to know what makes for good team defense. But the rest of the world has clearly gotten good enough, talent-wise, that the fact that our eighth man is an NBA star and nobody else's is doesn't do us any good. An offense is only going to get so good and there are real diminishing returns to adding more and more great players into the mix. Defense is half of the game, and if you want to win you need to plan with team defense in mind to at least some extent.