India, China, and South Korea (all countries with heavy STEM emphasis) together make up close to half of all foreign students in the US [1]. At just the graduate level, India and China contribute ~70% of all science and engineering students [2]. It would be disingenuous to pretend otherwise.

[1] http://www.iie.org/Services/Project-Atlas/United-States/Inte... [2] http://www.nsf.gov/statistics/seind12/pdf/c02.pdf