[WS:] I think the US is unique in its extreme regimentation of the school system. In no other country all kids are legally required to go through the same standardized curriculum for 12 years, enforced by standardized tests and threats of legal sanctions imposed on teachers.
The only thing that is non-standardized in US educational system is funding of schools. In this respect the US has it exactly backwards - in Europe school funding is centralized, but schools curriculum is diversified.
This has nothing to do with teacher quality (or lack thereof) but rather with extreme Taylorisation of work in 'Murika and also with the detrimental effect of the college system on K12 education. The demand for standardized testing comes from colleges, which see K12 education as mere preparation for college admission. Unfortunately, many liberals share this idea. Vocational or non-college education is typically frowned upon.
Wojtek