NCLB is set up to punish schools that don't meet their improvement goals. The schools, wary of being punished themselves, punish teachers whose students aren't meeting the goals.

While teachers are busy trying to teach basic math and language literacy to the bottom rung of the class, the students who could excel if they were challenged end up left behind.

For reasons beyond a teacher's control, a class may not meet the requirements, and the teacher is punished. You can look at a teacher's career and determine with reasonable accuracy whether the teacher is good, but looking at one or two year samples does not give the same accuracy. Yet that is exactly what NCLB encourages schools to do.

There was plenty I learned in grade school that standardized tests never tested. The optimal school and teacher strategy under NCLB is to strip out all that excess baggage and spend every waking moment figuring out how to get students to perform better only on what is tested.

I disagree with your notion that other countries are doing things right. They are doing things better, perhaps, or maybe the parents in other countries encourage students more not to give up when they're struggling with homework; the opposite of which is a major failing that seems to be common in America. An educational paradigm can be garbage but students will still learn more if it has support from parents.

Khan Academy's model or something even more radical is the direction all basic skills education needs to move toward. Teaching basic skills is critical, but they need to be taught in a way that both encourages under-performing students and that doesn't hold back better performing students. That's the only way to leave no child behind.