I'm a PhD research chemist and I know just enough to be able to read some of these papers. You are right. The burden of U.S. R&D in most topics is carried by foreign grad students and post-docs. And now, more and more of them are returning home rather than staying here. What the U.S. is losing, China, India and a few other countries are gaining.
My wife, who is also Japanese, decided she wants to become a pharmacist. She learned the hard way that the frame for her degree in sociology is worth more than the degree itself. We are churning out liberal arts majors, complete with left wing ideology, but there is almost no demand for anyone with a liberal arts degree. She is taking the prerequisites and was astonished how freshman chemistry and biology attendance drops in half by the end of the semester. She was also deeply offended at the attitude of many of the American students - talking in class, not paying attention, playing games on their laptops during lectures, etc. And now people are trying to get bastardized creationism into the schools. We will be drowing in ignorance in 20 years.
Every nation that has gone to 'war' against science has both lost the war and failed as a nation. Hopefully we won't go that route.