Massively increase pay for teachers, tripling or quadrupling pay at every level. Mandate a specific postgraduate qualification and a statutory minimum of continuing professional development. Recruit only the best and the brightest, specifically seeking out graduates from the best universities. Advertise teaching as a career on prime-time television. Put Obama on The Daily Show and Oprah to talk about the importance of teaching. In short, a concerted effort to make teaching every bit as prestigious as law or medicine. After a few years, require every teacher in the country to reapply for their own job. Relative to the Military or Social Security budgets, the cost would barely even register on the balance sheet.
We could quite easily live in a world where Asian parents push their kids into teaching, where Yale and Harvard vie to be the best school of education, where teaching is seen as a first choice rather than a last resort.
We don't, because we don't really care. We pretend that education matters, but really it's one of those things that you're supposed to care about but most people don't, like the environment or human rights. We don't care whether college students learn anything, only that they get a suitably prestigious certificate. We don't care whether high school graduates can meaningfully participate in society, only that they can pass the standardised tests, whatever they might be.
It is practically self-evident that we don't care about teaching. We all know that the current system is failing, but we aren't prepared to do the obvious things that would actually rescue it. For as long as we see education in the abstract as high status but teaching in practice as low status, we are doomed to watch our school system circle the drain.