I'm still not sure how to interpret your original post. Are you claiming that the source of the achievement gap is somehow inherent in "race"? Or are you simply pointing out the correlation to race, without making claims to its source (allowing for the actual source to be something else like income level)?
I'm claiming that either race directly, or something correlated with it, explains a large amount of test score variation. And once you correct for this, the US scores very well.
Also, should have linked to this post comparing Asian Americans to Asians.